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(e.g. optim, force):

Basic Keywords

Keyword Type Description
BS_KPOINT_PATHBlockK-point path for bandstructure calculation
CHARGEIntegerTotal charge of system
CLASSICAL_INFOBlockInclude classical point charges in the system
COND_CALC_MAX_EIGENLogicalCalculate maximum conduction-Hamiltonian eigenvalue at each NGWF CG optimisation step.
COND_CALC_OPTICAL_SPECTRALogicalCalculate matrix elements for use in optical absorption spectra
COND_ENERGY_GAPPhysicalEnergy gap between highest optimised and lowest unoptimised cond state
COND_ENERGY_RANGEPhysicalEnergy range of optimised cond states measured from HOMO
COND_FIXED_SHIFT LogicalKeep shift for projected conduction Hamiltonian constant in COND task
COND_INIT_SHIFTPhysicalInitial shifting factor for projected conduction Hamiltonian.
COND_KERNEL_CUTOFFPhysicalConduction state density kernel cutoff radius in bohr.
COND_MAXIT_LNVIntegerMaximum number of LNV iterations during conduction-NGWF optimisation.
COND_MINIT_LNVIntegerMinimum number of LNV iterations during conduction NGWF optimisation.
COND_NUM_STATESLogicalThe number of conduction states to be optimised.
COND_PLOT_JOINT_ORBITALSLogicalPlot orbitals in joint valence-conduction basis following COND task
COND_PLOT_VC_ORBITALS LogicalPlot orbitals in separate val cond bases following COND task
COND_READ_DENSKERNLogicalRead in the conduction density kernel from disk
COND_READ_TIGHTBOX_NGWFSLogicalRead in the conduction NGWFs from disk
COND_SHIFT_BUFFERPhysicalBuffer added to the highest calculated eigenvalue when updating the conduction shift
COND_SPEC_CALC_MOM_MAT_ELSLogicalCalculate optical matrix elements in momentum representation
COND_SPEC_CALC_NONLOC_COMMLogicalCalculate commutator between nonlocal potential and position operator
COND_SPEC_CONT_DERIVLogicalCalculate commutator between the nonlocal potential and position operator using continuous derivative in k-space
COND_SPEC_NONLOC_COMM_SHIFTRealFinite difference shift for calculating commutator between nonlocal potential and the position operator (if calculated using finite differences)
CONSTANT_EFIELDTextConstant electric field to be applied
CUBE_FORMATLogicalUse cube format for plot files
CUTOFF_ENERGYPhysicalEquivalent plane wave kinetic energy cutoff
DBL_GRID_SCALERealRatio of charge density / potential working grid to standard grid (1 or 2 only).
DDEC_CALCULATELogicalRun DDEC analysis.
DDEC_CLASSICAL_HIRSHFELDLogicalOutput results from classical Hirshfeld partitioning
DISPERSIONIntegerActivate dispersion corrections
DO_PROPERTIESLogicalPermit calculation of properties
DX_FORMATLogicalUse OpenDX format for plot files
EDFTLogicalEnable finite-temperature DFT calculations with the Ensemble-DFT method
EDFT_INIT_MAXITIntegerMaximum number of inner loop iterations with the EDFT method to be performed at the start of the calculation.
EDFT_MAXITIntegerMaximum number of inner loop iterations with the EDFT method.
EDFT_SMEARING_WIDTHPhysicalOccupation smearing width for EDFT calculations.
EDFT_SPIN_FIXIntegerNumber of NGWF CG iterations to hold the spin fixed. If negative, hold forever.
ELD_CALCULATELogicalCalculate electron localisation descriptors
ELD_FUNCTIONTextChoose which electron localisation descriptor to use during the properties calculation, either ELF or LOL
ETRANS_BULKLogicalCompute the bulk transmission coefficients of the individual leads defined in ETRANS_LEADS.
ETRANS_EMAXPhysicalHighest energy for the calculation of the transmission coefficients.
ETRANS_EMINPhysicalLowest energy for the calculation of the transmission coefficients
ETRANS_ENUMIntegerNumber of energy steps for the calculation of the transmission coefficients
ETRANS_LCRLogicalCompute the 'Left-Centre-Right' transmission coefficients between all leads defined in ETRANS_LEADS.
ETRANS_LEADSBlockDefines the atoms that form the leads for the calculation of the transport coefficients.
ETRANS_SETUPBlockTransport setup description
EXTERNAL_PRESSUREPhysicalValue of the input pressure Pin in the electronic enthalpy functional H=U+PV,
FINE_GRID_SCALERealSpacing of fine grid as multiple of standard grid
GEOM_LBFGSLogicalWhether to perform LBFGS rather than BFGS in a Geometry Optimization
GEOM_MAX_ITERIntegerMaximum number of geometry optimisation iterations
GEOM_METHODTextGeometry optimisation method
GEOM_PRECOND_TYPETextWhich pre-conditioner to use for the LBFGS geometry optimiser
GRD_FORMATLogicalUse.grdformat for plot files
HOMO_DENS_PLOTIntegerNumber of canonical orbital densities to plot below HOMO
HOMO_PLOTIntegerNumber of canonical orbitals to plot below HOMO
HUBBARDSCF_ON_THE_FLYLogicalActivate a non-variational on-the-fly form of projector self-consistency in DFT+U or cDFT, in which the projectors are updated whenever the NGWFs are. task : HUBBARDSCF is then not needed.
HUBBARD_CONV_WINIntegerThe minimum number of Hubbard projector update steps satisfying the incremental energy tolerance hubbard_energy_tol required for convergence in task : HUBBARDSCF.
HUBBARD_ENERGY_TOLPhysicalThe maximum incremental energy change between Hubbard projector update steps allowed for converge in task : HUBBARDSCF.
HUBBARD_FUNCTIONALIntegerThe form of DFT+U energy term used.
HUBBARD_MAX_ITERIntegerThe maximum allowed number of Hubbard projector update steps taken in a projector self-consistent DFT+U or cDFT calculation in task : HUBBARDSCF.
HUBBARD_NGWF_SPIN_THRESHOLDPhysicalThe incremental change in energy, in total-energy minimisation, at which any spin-splitting (Zeeman) type term in DFT+U is switched off, and the minimisation history reset.
HUBBARD_PROJ_MIXINGRealThe fraction of previous Hubbard projector to mix with new for projector self-consistent DFT+U or cDFT in task : HUBBARDSCF. Not found to be necessary.
HUBBARD_READ_PROJECTORSLogicalRead Hubbard projectors from .tightbox_hub_projs file in restart calculations involving DFT+U.
HUBBARD_TENSOR_CORRIntegerThe form of correction used to correct for any nonorthogonality between Hubbard projectors.
IS_BULK_PERMITTIVITYRealDefines the relative dielectric permittivity of the solvent
IS_IMPLICIT_SOLVENTLogicalMakes the calculation use implicit solvent
IS_INCLUDE_APOLARLogicalTurns on the apolar term (cavitation, solute-solvent dispersion-repulsion) in an implicit solvent calculation
IS_INCLUDE_CAVITATIONLogicalKEYWORD REPLACED BY IS_INCLUDE_APOLAR in v4.4.6 (main branch) and v4.5.1 (devel branch). Turns on the cavitation term in an implicit solvent calculation
IS_SOLVENT_SURFACE_TENSIONPhysicalUsed to define the surface tension of the solvent, NOW SUPERSEDED BY IS_SOLVENT_SURF_TENSION (with a change in meaning). DO NOT USE THIS KEYWORD ANYMORE.
IS_SOLVENT_SURF_TENSIONPhysicalDefines the surface tension of the solvent. This keyword supersedes IS_SOLVENT_SURFACE_TENSION (but has a different meaning, see doc).
KERNEL_CHRISTOFFEL_UPDATELogicalPreserve the density-matrix (idempotency, norm) to first order when the NGWFs change.
KERNEL_CUTOFFPhysicalDensity kernel cutoff radius.
KE_DENSITY_CALCULATELogicalCalculate kinetic energy density
LATTICE_CARTBlockSimulation cell lattice vectors in Cartesian coordinates
LUMO_DENS_PLOTIntegerNumber of canonical orbital densities to plot above LUMO
LUMO_PLOTIntegerNumber of canonical orbitals to plot above LUMO
MD_DELTA_TPhysicalMolecular dynamics time step
MD_NUM_ITERIntegerNumber of molecular dynamics iterations
MD_RESET_HISTORYIntegerFull reset of the NGWFs and density kernel SCF cycle every N MD steps. New initial guesses for the electronic degrees of freedom are built according to COREHAM_DENSKERN_GUESS and SPECIES_ATOMIC_SET.
MD_RESTARTLogicalRestart MD from previous backup files
NBO_LIST_PLOTNBOBlockThe list of NBO_PLOT_ORBTYPE orbitals to be plotted.
NBO_PLOT_ORBTYPETextThe type of gennbo-generated orbitals to read and plot.
NBO_WRITE_DIPOLELogicalComputes and writes dipole matrix to FILE.47
NBO_WRITE_NPACOMPLogicalWrites NAO charges for all orbitals to standard output.
NBO_WRITE_SPECIESBlockBlock of lists of species to be included in the partial matrix output of seedname_nao_nbo.47.
NNHOLogicalConvert NGWFs into non-orthogonal natural hybrid orbitals
OUTPUT_DETAILTextSpecify level of output detail
PAWLogicalActivate PAW calculation.
PHONON_ANIMATE_LISTBlockList of Gamma-point modes (where 1 is the lowest) for which to write xyz animation files.
PHONON_ANIMATE_SCALERealRelative scale of the amplitude of the vibration in the xyz animation.
PHONON_DELTATPhysicalTemperature step for the computation of thermodynamic quantities.
PHONON_DISP_LISTBlockList of force constant calculations to perform for Stage 2 in phonon calculations (i.e. in the case of phonon_farming_task 2 or 0).
PHONON_DOSLogicalCalculate the phonon DOS and write to file.
PHONON_DOS_DELTARealFrequency step for the phonon DOS calculation (in 1/cm).
PHONON_DOS_MAXRealUpper bound of the phonon DOS range (in 1/cm).
PHONON_DOS_MINRealLower bound of the phonon DOS range (in 1/cm).
PHONON_ENERGY_CHECKLogicalPerform a sanity check that the total energy does not decrease upon ionic displacement.
PHONON_EXCEPTION_LISTBlockList of exceptions to the global defaults defined by PHONON_VIB_FREE, PHONON_SAMPLING, and PHONON_FINITE_DISP.
PHONON_FARMING_TASKIntegerSelect which phonon calculation stage to perform. Can be either 1,2,3 for a single stage, or 0 for all stages. Default is 0.
PHONON_FINITE_DISPPhysicalIonic displacement distance.
PHONON_FMAXPhysicalMaximum ionic force allowed in the unperturbed system.
PHONON_GRIDBlockDefinition of the regular grid of q-points used in phonon calculations for the computation of thermodynamic quantities and the phonon DOS.
PHONON_MIN_FREQPhysicalMinimum phonon frequency for the computation of thermodynamic quantities, expressed as an energy; frequencies lower than this are discarded.
PHONON_QPOINTSBlockList of additional q-points for which to calculate the phonon frequencies, in fractional coordinates of the reciprocal unit cell vectors.
PHONON_SAMPLINGIntegerSelects which finite-difference formula to use.
PHONON_SKLogicalUse a Slater-Koster style interpolation for q-points instead of a real-space cutoff of the force constants matrix elements.
PHONON_TMAXPhysicalUpper bound of the temperature range for the computation of thermodynamic quantities.
PHONON_TMINPhysicalLower bound of the temperature range for the computation of thermodynamic quantities, expressed as an energy (k_B T).
PHONON_VIB_FREEIntegerDefault allowed vibrational degrees of freedom for all ions.
PHONON_WRITE_EIGENVECSLogicalWrite the eigenvectors as well as the phonon frequencies to file for the additional q-points.
PLOT_NBOLogicalInstructs ONETEP to read the relevant orbital transformation output from gennbo, determined by the flag NBO_PLOT_ORBTYPE and plots the orbitals specified in the NBO_LIST_PLOTNBO block.
POLARISATION_CALCULATELogicalActivate Polarisation Calculation
POPN_BOND_CUTOFFPhysicalMulliken population analysis bond length cutoff
POPN_CALCULATELogicalPerform Mulliken population analysis
POSITIONS_ABSBlockAtomic positions in Cartesian coordinates
READ_DENSKERNLogicalRead density kernel to restart
READ_SW_NGWFSLogicalRead NGWFS in spherical waves format to restart
READ_TIGHTBOX_NGWFSLogicalRead NGWFs to restart
RMS_KERNEL_MEASURELogicalUse a legacy measure of the commutator of the density-matrix and Hamiltonian, given by the root mean squared value of the doubly-covariant NGWF representation of their commutator.
SPECIESBlockAtomic species information
SPECIES_CONDBlockAtomic species information for conduction NGWFs
SPECIES_CONSTRAINTSBlockAtomic species geometry optimisation constraints
SPECIES_LDOS_GROUPSBlockLocal Density of States species group definitions
SPECIES_NGWF_PLOTBlockAtomic species for plotting NGWFs
SPECIES_POTBlockPseudopotentials for atomic species
SPINIntegerTotal spin of system
SPIN_POLARIZEDLogicalPerform spin polarized calculation
SPREAD_CALCULATELogicalActivate Calculation of NGWF Spreads
SUPERCELLBlockDefinition of the supercell used for crystalline materials in phonon calculations.
TASKTextSpecify task
THREADS_MAXIntegerNumber of threads in outer loops.
THREADS_NUM_FFTBOXESIntegerNumber of threads to use in OpenMP-parallel FFTs.
THREADS_NUM_MKLIntegerThe number of threads to use in MKL routines (matrix-matrix multiplications, inverses, diagonalisations etc.).
WRITE_DENSITY_PLOTLogicalWrite out charge density and electrostatic potential for plotting
WRITE_DENSKERNLogicalWrite density kernel for future restart
WRITE_FORCESLogicalInclude ionic forces in output
WRITE_NBOLogicalEnables Natural Population Analysis (NPA) and writing of gennbo input file seedname_nao_nbo.47
WRITE_NGWF_PLOTLogicalWrite out NGWFs for plotting
WRITE_SW_NGWFSLogicalWrite NGWFs in spherical waves format for future restart
WRITE_TIGHTBOX_NGWFSLogicalWrite NGWFs for future restart
WRITE_XYZLogicalWrite .xyz file of atom coordinates for visualisation
XC_FUNCTIONALTextExchange-correlation functional

Intermediate Keywords

Keyword Type Description
BSUNFLD_KPOINT_PATHBlockK-point path for bandstructure unfolding calculation
BSUNFLD_TRANSFORMATIONIntegerTransformation matrix (flattened) between primitive-cell and supercell lattice vectors when unfolding bandstructure
BS_KPOINT_PATH_SPACINGPhysicalK-point spacing along the bandstructure path
BS_METHODTextWhich method to use for the calculation of bandstructures
BS_NUM_EIGENVALUESIntegerNumber of energy eigenvalues to print in a bandstructure calculation
CDFT_ATOM_CHARGELogicalActivate atom charge-constrained-DFT mode. This mode is incompatible with any other cDFT-mode.
CDFT_ATOM_SPINLogicalActivate atom magnetic-moment-constrained-DFT mode. This mode is incompatible with any other cDFT-mode.
CDFT_CG_THRESHOLDRealSpecifies the convergence threshold for the RMS gradient of the constraining potentials (Uq/s).
CDFT_CHARGE_ACCEPTOR_TARGETRealTargeted acceptor-group electron population for acceptor-group charge-constrained-DFT mode [CDFT_GROUP_CHARGE_ACCEPTOR = T].
CDFT_CHARGE_DONOR_TARGETRealTargeted donor-group electron population for donor-group charge-constrained-DFT mode [CDFT_GROUP_CHARGE_DONOR = T]
CDFT_CONTINUATIONLogicalContinue a constraining potential (Uq/s) optimisation from a previous run using the .cdft file with the latest cDFT-potentials.
CDFT_ELEC_ENERGY_TOLPhysicalTolerance on energy change per atom during CDFT optimisation. If negative, the option is deactivated.
CDFT_GROUP_CHARGE_ACCEPTORLogicalActivate acceptor-group charge-constrained-DFT mode.
CDFT_GROUP_CHARGE_DIFFLogicalActivate group charge-difference constrained-DFT mode.
CDFT_GROUP_CHARGE_DIFF_TARGET RealTargeted electron population difference between acceptor and donor group for group-charge-difference constrained-DFT mode [CDFT_GROUP_CHARGE_DIFF =T].
CDFT_GROUP_CHARGE_DONORLogicalActivate donor-group charge-constrained-DFT mode.
CDFT_GROUP_CHARGE_DOWN_ONLY LogicalConstrain only SPIN-DOWN channel in CDFT_GROUP_CHARGE_ACCEPTOR, CDFT_GROUP_CHARGE_DONOR and CDFT_GROUP_CHARGE_DIFF modes.
CDFT_GROUP_CHARGE_UP_ONLY LogicalConstrain only SPIN-UP channel in CDFT_GROUP_CHARGE_ACCEPTOR, CDFT_GROUP_CHARGE_DONOR and CDFT_GROUP_CHARGE_DIFF modes.
CDFT_GROUP_SPIN_ACCEPTOR LogicalActivate acceptor-group magnetic-moment constrained-DFT mode.
CDFT_GROUP_SPIN_DIFF LogicalActivate group magnetic-moment-difference constrained-DFT mode.
CDFT_GROUP_SPIN_DIFF_TARGET RealTargeted magnetic-moment difference between acceptor and donor group for group-magnetic-moment-difference constrained-DFT mode [CDFT_GROUP_SPIN_DIFF =T].
CDFT_GROUP_SPIN_DONORLogicalActivate donor-group magnetic-moment constrained-DFT mode.
CDFT_HUBBARDLogicalActivate the constrained-DFT+U functionality. It requires specifications of a positive value for the Hubbard correction (Uh) in the CONSTRAINED_DFT Block.
CDFT_MAX_GRAD RealSpecifies the convergence threshold for the maximum value of the constraining-potential (Uq/s) gradient at any cDFT-site.
CDFT_MULTI_PROJ LogicalActivate the “as many cDFT-projectors as NGWFs” cDFT-mode.
CDFT_PRINT_ALL_OCCLogicalPrint detailed information of occupancies for al the cDFT-sites, for OUTPUT_DETAIL = VERBOSE.
CDFT_READ_PROJLogicalRead cDFT-projectors from .tightbox_hub_proj file.
CDFT_SPIN_ACCEPTOR_TARGET RealTargeted group magnetic-moment for acceptor-group magnetic-moment constrained-DFT mode [CDFT_GROUP_SPIN_ACCEPTOR = T].
CDFT_SPIN_DONOR_TARGETRealTargeted group magnetic-moment for donor-group magnetic-moment constrained-DFT mode [CDFT_GROUP_SPIN_DONOR = T].
CDFT_TRIAL_LENGTHRealSpecifies initial trial length for first step of constraining-potential (Uq/s) conjugate gradients optimisation.
CI_CDFT LogicalPerform a Configuration Interaction calculation based on constrained-DFT configurations.
CI_CDFT_NUM_CONFIntegerSpecifies the number of constrained-DFT configuration available for a CI_CDFT = T simulation.
COND_NUM_EXTRA_ITSIntegerNumber of iterations of pre-optimisation stage during COND task
COND_NUM_EXTRA_STATESIntegerNumber of additional conduction states optimised during the pre-optimisation stage
CONSTRAINED_DFTBlockManages constrained-DFT simulations.
COULOMB_CUTOFF_LENGTHPhysicalLength of cylinder or width of slab for cutoff coulomb interaction
COULOMB_CUTOFF_RADIUSPhysicalRadius of sphere or cylinder for cutoff coulomb interaction
COULOMB_CUTOFF_TYPETextType of cutoff coulomb interaction: NONE, SPHERE, CYLINDER, SLAB, WIRE
COULOMB_CUTOFF_WRITE_INTLogicalWrite real-space cutoff Coulomb interaction scalarfield
DDEC_CONV_THRESHPhysicalThreshold for DDEC charges to be considered converged.
DDEC_CORE_MAXITIntegerMaximum number of DDEC core iterations.
DDEC_IH_FRACTIONRealFraction of reference ion weighting used in DDEC partitioning.
DDEC_IH_IONIC_RANGEIntegerRange of ionic charges for DDEC Reference densities
DDEC_MAXITIntegerMaximum number of DDEC iterations.
DDEC_MOMENTIntegerCalculate DDEC AIM moment of order n.
DDEC_MULTIPOLELogicalCalculate DDEC AIM dipoles and quadrupoles.
DDEC_RAD_NPTSIntegerNumber of atom-centered shells used for spherical averaging and storing the DDEC AIM density profiles.
DDEC_RAD_RCUTPhysicalRadius of the largest spherical shell for DDEC.
DDEC_WRITE_RADLogicalWrite AIM spherically-averaged density profiles.
DENSE_THRESHOLDRealThreshold for matrix segments to be treated as dense
DOS_SMEARPhysicalHalf-width for Gaussian smearing of density of states
DX_FORMAT_COARSELogicalMakes the .dx files (see DX_FORMAT) smaller by outputting only odd points along every axis, discarding even points.
DX_FORMAT_DIGITSIntegerSelects the number of significant digits in .dx file (see DX_FORMAT) output.
EDFT_COMMUTATOR_THRESPhysicalTolerance on the total Hamiltonian-density matrix commutator during EDFT inner loop.
EDFT_ENERGY_THRESPhysicalTolerance on total energy change during EDFT inner loop.
EDFT_ENTROPY_THRESPhysicalTolerance on total entropy change during EDFT inner loop.
EDFT_FERMI_THRESPhysicalTolerance on total Fermi energy change during EDFT inner loop.
EDFT_FREE_ENERGY_THRESPhysicalTolerance on total free energy change during EDFT inner loop.
EDFT_RMS_GRADIENT_THRESRealTolerance on the total occupancies RMS gradient during EDFT inner loop.
ELEC_ENERGY_TOLPhysicalTolerance on total energy change during NGWF optimisation.
ELEC_FORCE_TOLPhysicalTolerance on maximum force change per electronic optimisation step during NGWF optimisation
ETRANS_CALCULATE_LEAD_MULogicalCalculate the lead chemical potentials via a non-self consistent band structure calculation.
ETRANS_ECMPLXPhysicalThe complex energy used to select the retarded Green's function. If set too small, instabilities may occur and the calculation of the Green's function may fail.
ETRANS_EREFPhysicalIf ETRANS_EREF_METHOD = REFERENCE, this defines the reference energy about which transmission is calculated.
ETRANS_EREF_METHODTextThe method to determine the reference energy for the calculation of transmission coefficients.
ETRANS_LEAD_NKPOINTSIntegerThe number of kpoints the lead band structure is calculated for.
ETRANS_WRITE_HSLogicalWrite the lead and LCR Hamiltonian and Overlap matrices to disk for further analysis.
EXACT_LNVLogicalUse Li-Nunes-Vanderbilt algorithm (not Millam-Scuseria variant)
EXTRA_N_SWIntegerGenerate extra spherical waves for NGWF representation (the extra SW will suffer of aliasing)
FFTBOX_BATCH_SIZEIntegerNumber of NGWFs in each batch of fftboxes
FFTBOX_PREFTextPreferred FFT box size
FOELogicalEnable calculation of the density kernel with a Fermi Operator Expansion approach in finite-temperature DFT calculations with the Ensemble-DFT method
FOE_AVOID_INVERSIONSLogical Avoid performing any inversions or using any inverses in the FOE method
FOE_CHEBY_THRESRealThe maximum error threshold on the Chebyshev expansions in the FOE
FOE_CHECK_ENTROPYLogical Validate the FOE entropy approximation against a simple quadratic form
FOE_MU_TOLPhysicalTolerance for stopping in FOE chemical potential search.
FOE_TEST_SPARSITYLogicalTest the quality of the H^2 sparsity pattern for K
GEOM_BACKUP_ITERIntegerBackup frequency for geometry optimisation
GEOM_CONTINUATIONLogicalContinue a previous geometry optimisation
GEOM_CONVERGENCE_WINIntegerNumber of geometry optimisation iterations for convergence criteria to be met
GEOM_DISP_TOLPhysicalDisplacement convergence tolerance for geometry optimisation
GEOM_ENERGY_TOLPhysicalEnergy convergence tolerance for geometry optimisation
GEOM_FORCE_TOLPhysicalForce convergence tolerance for geometry optimisation
GEOM_FREQUENCY_ESTPhysicalEstimated average phonon frequency for geometry optimisation
GEOM_LBFGS_MAX_UPDATESIntegerMaximum number of force and position updates to store when using the LBFGS method
GEOM_MODULUS_ESTPhysicalEstimated bulk modulus for geometry optimisation
GEOM_PRECOND_EXP_ARealA value of the EXP pre-conditioner for LBFGS geometry optimisation with pre-conditioning
GEOM_PRECOND_EXP_C_STABPhysicalStabilization constant of EXP pre-conditioner for LBFGS geometry optimisations
GEOM_PRECOND_EXP_R_CUTPhysicalCutoff distance for EXP pre-conditioner for LBFGS geometry optimisations
GEOM_PRECOND_FF_C_STABPhysicalStabilization constant of FF pre-conditioner for LBFGS geometry optimisations
GEOM_PRECOND_FF_R_CUTPhysicalCutoff distance for FF pre-conditioner for LBFGS geometry optimisations
H2DENSKERN_SPARSITYLogicalEnable the AQuA-FOE method
HUBBARDBlockActivate DFT+U(+J) (or LDA+U) functionality.
ISOSURFACE_CUTOFFRealDetermines the cutoff density alpha of the electronic density isosurface defining the volume V used in the electronic enthalpy method.
IS_AUTO_SOLVATIONLogicalAutomatically runs a calculation in vacuum before any calculation that requires implicit solvation.
IS_BC_COARSENESSIntegerBlock size for bulk charge coarse-graining in open boundary conditions
IS_BC_SURFACE_COARSENESSIntegerBlock size for surface charge coarse-graining in open boundary conditions
IS_CHECK_SOLV_ENERGY_GRADLogicalChecks the gradient of solvation energy by finite differences
IS_CORE_WIDTHPhysicalImplicit solvent: radius around each core where the permittivity is set to unity.
IS_DENSITY_THRESHOLDRealThe parameter rho_0 in the definition of the cavity (atomic units)
IS_DIELECTRIC_FUNCTIONTextDetermines how the dielectric cavity is generated
IS_DIELECTRIC_MODELTextDetermines how the dielectric cavity is generated
IS_DISCRETIZATION_ORDERIntegerThe discretization order used for the defect correction in the multigrid calculation
IS_MULTIGRID_DEFECT_ERROR_TOLRealStop criterion for the defect correction in the multigrid calculation
IS_MULTIGRID_ERROR_TOLRealStop criterion for the multigrid calculation
IS_PBETextChooses the equation to be solved in implicit solvation.
IS_SC_STERIC_MAGNITUDEPhysicalPrefactor in soft-core steric potential in implicit solvation with Boltzmann ions.
IS_SEPARATE_RESTART_FILESLogicalUses a different set of files (.vacuum_dkn and .vacuum_tightbox_ngwfs) to construct the solute cavity for implicit solvation.
IS_SMEARED_ION_REPLogicalTurns on the smeared ion representation for electrostatics calculation.
IS_SMEARED_ION_WIDTHPhysicalCharacteristic width for the Gaussian smearing of ions.
IS_SOLVATION_BETARealThe parameter beta in the definition of the cavity (unitless)
IS_SOLVATION_METHODTextChooses between the direct and corrective solvation approach.
IS_SOLVATION_OUTPUT_DETAILTextControls details of additional implicit solvent output
KERNEL_DIIS_MAXITIntegerMaximum number of inner loop DIIS iterations
KERNEL_DIIS_SCHEMETextEnable self-consistent density kernel mixing or Hamiltonian mixing in the inner loop
KERNEL_DIIS_SIZEIntegerMaximum number of density kernels or Hamiltonians to be mixed during inner loop DIIS
LIBXC_C_FUNC_IDIntegerFunctional ID for correlation functional in a LIBXC calculation.
LIBXC_X_FUNC_IDIntegerFunctional ID for exchange functional in a LIBXC calculation.
LNV_CHECK_TRIAL_STEPSLogicalCheck stability of kernel at each trial step during LNV
LNV_THRESHOLD_ORIGRealConvergence threshold for density kernel RMS gradient
LR_TDDFT_RPABooleanIf the flag is set to True, a full TDDFT calculation in the so-called "Random Phase Approximation" will be performed, rather than invoking the Tamm-Dancoff approximation
MAXIT_CDFT_U_CG IntegerSpecifies the maximum number of iterations for the constraining potentials (Uq/s) conjugate gradients optimisation.
MAXIT_HOTELLINGIntegerMaximum number of iterations for inverting the overlap matrix
MAXIT_LNVIntegerMaximum number of density kernel iterations
MAXIT_NGWF_CGIntegerMaximum number of NGWF conjugate gradient iterations
MAXIT_PALSER_MANOIntegerMaximum number of Palser-Manolopoulos iterations
MAXIT_PENIntegerMaximum number of penalty functional iterations
MINIT_LNVIntegerMinimum number of density kernel iterations
NBO_SPECIES_NGWFLABELBlockOptional user-defined (false) lm-label for NGWFs according to gennbo convention.
NEB_CI_DELAYIntegerDelay before enabling climbing image in NEB calculations.
NEB_PRINT_SUMMARYBooleanPrint NEB summary to stdout
NGWF_MAX_GRADRealConvergence threshold for maximum NGWF gradient at any psinc grid point.
NGWF_THRESHOLD_ORIGRealConvergence threshold for NGWF RMS gradient
NUM_EIGENVALUESIntegerNumber of Kohn-Sham states above and below Fermi level to calculate
NUM_IMAGESIntegerNumber of ONETEP instances to run in parallel
OPENBC_HARTREELogicalSwitches from periodic to open boundary conditions in the calculation of Hartree energy
OPENBC_ION_IONLogicalSwitches from periodic to open boundary conditions in the calculation of ion-ion energy
OPENBC_PSPOTLogicalSwitches from periodic to open boundary conditions in the calculation of local pseudopotential energy
PADDED_LATTICE_CARTBlockThe simulation cell lattice vectors for the padded cell for Cutoff Coulomb
PEN_PARAMRealPenalty functional parameter in hartree
PRODUCT_ENERGYPhysicalProduct energy in NEB calculation
PRODUCT_ROOTNAMETextProduct restart files' rootname in NEB calculation
REACTANT_ENERGYPhysicalReactant energy in NEB calculation
REACTANT_ROOTNAMETextReactant restart files' rootname in NEB calculation
READ_HAMILTONIANLogicalRead the Hamiltonian matrix from a file (EDFT only)
READ_MAX_LIntegerSet maximum SW angular momentum (l number) when reading from file
RUN_TIMERealThe maximum allocated run time for this job (in seconds)
SMOOTHING_FACTORRealSmoothing factor for electronic volume step function.
SOL_IONSBlockDescribes the kinds of Boltzmann ions in implicit solvent.
SPECIES_ATOMIC_SETBlockAtomic species initial NGWFs
THERMOSTATBlockMolecular dynamics thermostat
THREADS_PER_CELLFFTIntegerNumber of threads to use in OpenMP-parallel FFTs on simulation cell.
TIMINGS_LEVELIntegerSet level of detail in timings
TSSEARCH_DISP_TOLPhysicalTransition state search displacement tolerance
TSSEARCH_ENERGY_TOLPhysicalEnergy convergence tolerance for transition state searching.
TSSEARCH_FORCE_TOLPhysicalTransition state search force tolerance
TSSEARCH_LSTQST_PROTOCOLTextTransition state search LSTQST protocol
TSSEARCH_METHODTextTransition state search method
WRITE_CONVERGED_DK_NGWFSLogicalOnly write Density Kernel and NGWFs to disk upon convergence of NGWF optimisation.
WRITE_HAMILTONIANLogicalWrite the Hamiltonian matrix on a file (EDFT only)
WRITE_MAX_LIntegerSet maximum SW angular momentum (l number) when writing to file

Expert Keywords

Keyword Type Description
CDFT_CG_MAXRealSpecifies the maximum number of constraining potential (Uq/s) conjugate gradient iterations between resets.
CDFT_CG_MAX_STEPRealMaximum length of trial step for the constraining potential (Uq/s) optimisation line search.
CDFT_CG_TYPETextSpecifies the variant of the conjugate gradients algorithm used for the optimization of the constraining potentials (Uq/s).
CDFT_GURU LogicalTell ONETEP you are a cDFT-expert and prevent it from initialising the active |Uq/s| to the failsafe value of 1 eV, overwriting the values entered in the CONSTRAINED_DFT (Uq/s) block.
CHECK_ATOMSLogicalCheck atoms are a reasonable distance apart
COMMS_GROUP_SIZEIntegerSize of a comms group
COREHAM_DENSKERN_GUESSLogicalInitialize density kernel by simple diagonalisation
DDEC_INTERP_RAD_DENSLogicalTrilinear postprocessing interpolation of converged DDEC AIM density
DDEC_MIN_SHELL_DENSRealMinimum number of points lying in each spherical shell for DDEC.
DDEC_REFDENS_INITLogicalInitialize DDEC AIM densities as neutral atom reference densities.
DDEC_ZERO_THRESHOLDRealThreshold for density on grid to be excluded in order to avoid division by zero.
DELTA_E_CONVLogicalUse consecutive energy gains as NGWF convergence criterion
DENSE_FOELogicalUse a dense matrix representation of the density kernel in the Fermi Operator Expansion approach
EDFT_EXTRA_BANDSIntegerNumber of extra energy bands in EDFT calculations.
EDFT_MAX_STEPRealMaximum step length for the line-search update in the inner loop of EDFT calculations.
EDFT_ROUND_EVALSIntegerRound up the energy eigenvalues in EDFT calculations.
EDFT_WRITE_OCCLogicalWrite occupancies in a file.
EIGENSOLVER_ABSTOLRealPrecision to which ScaLapack PDSYGVX eigensolver will resolve the eigenvalues.
EIGENSOLVER_ORFACRealPrecision to which ScaLapack PDSYGVX eigensolver will orthonormalise the eigenvectors.
ELEC_CG_MAXIntegerReset frequency for NGWF conjugate gradients
ETRANS_LEAD_DISP_TOLPhysicalThe maximum acceptable difference in the translation vectors between the atoms in a lead, and the corresponding atoms in the lead principle layer.
ETRANS_SAME_LEADSLogicalUse the same self-energy for all the leads.
EVEN_PSINC_GRIDLogicalForce even number of points in the simulation-cell psinc grid.
EXTERNAL_BC_FROM_CUBELogicalRead in external boundary conditions for the electrostatic potential
GEOM_LBFGS_BLOCK_LENGTHIntegerHow many force and position updates to store before reallocation of the history vector storage in an unbounded LBFGS calculation
GEOM_PRECOND_EXP_MUPhysicalmu value for EXP preconditioner
GEOM_PRECOND_EXP_R_NNPhysicalAtomic nearest neighbour distance for EXP pre-conditioner for LBFGS geometry optimisations
GEOM_PRINT_INV_HESSIANLogicalPrint inverse Hessian
GEOM_RESET_DK_NGWFS_ITERLogicalNumber of geom iterations between resets of kernel and NGWFs
GEOM_REUSE_DK_NGWFSLogicalRe-use density kernel and NGWFs during geometry optimisation steps
IMAGE_SIZESTextIndividual sizing of ONETEP images
INITIAL_DENS_REALSPACERealConstruct initial density in real space from atomsolver density
IS_APOLAR_SCALING_FACTORRealScaling factor applied to the apolar solvation term.
IS_BC_THRESHOLDRealCharge density threshold for bulk charge coarse-graining in open boundary conditions
IS_DIELECTRIC_EXCLUSIONSBlockDescribes solvent-excluded regions, if any.
IS_DIELECTRIC_EXCLUSIONS_SMEARPhysicalLength scale that defines the extent of the smearing of dielectric exclusion region boundaries. For more details, see the implicit solvation documentation.
IS_HC_STERIC_CUTOFFPhysicalImplicit solvent: cutoff radius for hard-core steric potential.
IS_MULTIGRID_ERROR_DAMPINGBooleanTurn on error damping in the multigrid defect-correction procedure.
IS_MULTIGRID_MAX_ITERSIntegerMaximum number of iterations for the multigrid solver
IS_MULTIGRID_NLEVELSIntegerNumber of multigrid levels for the multigrid solver
IS_MULTIGRID_VERBOSEBooleanOutput cross-sections of quantities that are of interest during multigrid calculations to text files.
IS_MULTIGRID_VERBOSE_YPhysicalSpecifies the offset along the Y axis for cross-sections performed with IS_MULTIGRID_VERBOSE.
IS_MULTIGRID_VERBOSE_ZPhysicalSpecifies the offset along the Z axis for cross-sections performed with IS_MULTIGRID_VERBOSE.
IS_PBE_BC_DEBYE_SCREENINGBooleanSpecifies whether boundary conditions in implicit solvation with Boltzmann terms should use Debye screening (lambda*exp) factor.
IS_PBE_EXP_CAPDoubleSets a numerical cap at the arguments in the exp() in Poisson-Boltzmann terms in implicit solvation.
IS_PBE_TEMPERATUREDoubleSets the temperature for the Boltzmann term in implicit solvation.
IS_PBE_USE_FASBooleanSpecifies whether the full aproximation scheme (FAS) should be used for the solution of the Poisson-Boltzmann equation in implicit solvation.
IS_SC_STERIC_CUTOFFPhysicalCutoff radius for soft-core steric potential in implicit solvation with Boltzmann ions.
IS_SC_STERIC_SMOOTHING_ALPHA PhysicalSmoothing factor alpha in soft-core steric potential in implicit solvation with Boltzmann ions.
IS_STERIC_WRITEBooleanSpecifies whether the steric potential (used in implicit solvation with Boltzmann ions) is to be written to a (dx/cube/grd) file.
IS_SURFACE_THICKNESSRealSurface film thickness (in atomic units of charge density) used for the determination of cavity surface area
KERNEL_DIIS_COEFFRealFraction of the output density kernel or Hamiltonian matrix for linear-mixing inner loop DIIS
KERNEL_DIIS_CONV_CRITERIATextConvergence criteria for inner loop DIIS
KERNEL_DIIS_LINEAR_ITERIntegerNumber of linear-mixing iterations preceeding Pulay or LiST mixing in the inner loop DIIS method
KERNEL_DIIS_LSHIFTPhysicalLevel-shifting energy during inner loop DIIS.
KERNEL_DIIS_LS_ITERIntegerNumber of inner loop DIIS iterations with level-shifting enabled.
KERNEL_DIIS_THRESHOLDRealConvergence threshold for inner loop DIIS
KERNEL_UPDATELogicalUpdate density kernel during NGWF line search
K_ZEROPhysicalParameter for kinetic energy preconditioning.
LNV_CG_MAX_STEPRealMaximum length of trial step for kernel optimisation line search
LNV_CG_TYPETextVariant of conjugate gradient algorithm to use for density kernel optimisation
LOCPOT_SCHEMETextScheme for symmetrising local potential matrix
LR_TDDFT_ANALYSISLogicalIf the flag is set to True, a full cubic-scaling analysis of each TDDFT excitation is performed in which the response density is decomposed into dominant Kohn-Sham transitions.
LR_TDDFT_CG_THRESHOLDRealThe keyword specifi es the convergence tolerance on the sum of the n TDDFT excitation energies.
LR_TDDFT_JOINT_SETLogicalIf the flag is set to T, the joint NGWF set is used to represent the conduction space in the LR-TDDFT calculation.
LR_TDDFT_KERNEL_CUTOFFPhysicalKeyword sets a truncation radius on all response density kernels in order to achieve linear scaling computational eff ort with system size.
LR_TDDFT_MAXIG_CGIntegerThe maximum number of conjugate gradient iterations the algorithm will perform.
LR_TDDFT_MAXIT_PENIntegerThe maximum number purifi cation iterations performed per conjugate gradient step.
LR_TDDFT_NUM_STATESIntegerThe keyword specifi es how many excitations we want to converge.
LR_TDDFT_PENALTY_TOLRealKeyword sets a tolerance for the penalty functional.
LR_TDDFT_PROJECTORLogicalIf the flag is set to True, the conduction density matrix is redefi ned to be a projector onto the entire unoccupied subspace.
LR_TDDFT_RESTARTLogicalIf the flag is set to True, the algorithm reads in LR_TDDFT_NUM_STATES response density kernels in .dkn format and uses them as initial trial vectors for a restarted LR-TDDFT calculation.
LR_TDDFT_TRIPLETLogicalFlag that decides whether the LR_TDDFT_NUM_STATES states to be converged are singlet or triplet states.
LR_TDDFT_WRITE_DENSITIES LogicalIf the flag is set to True, the response density, electron density and hole density for each excitation is computed and written into a .cube file.
LR_TDDFT_WRITE_KERNELS LogicalIf the flag is set to T, the TDDFT response density kernels are printed out at every conjugate gradient iteration. These files are necessary to restart a LR-TDDFT calculation.
MAX_RESID_HOTELLINGRealMaximum residual value allowed when inverting overlap matrix
MG_DEFCO_FD_ORDERInteger Order of finite differences to use in the high-order defect correction component of the multigrid solver.
MG_GRANULARITY_POWERInteger Power of 2 which gives multigrid granularity.
MG_TOL_RES_RELRealRelative tolerance in norm of residual for defect correction procedure in multigrid solver.
MIX_DKN_INIT_NUMIntegerLength of the initialization phase for the density kernel.
MIX_DKN_INIT_TYPETextSpecifies the mixing scheme used during the initialisation phase for the density kernel.
MIX_DKN_NUMIntegerNumber of independent coefficients used to build new guesses for the density kernel.
MIX_DKN_RESETIntegerEvery N MD steps, the density kernel mixing/extrapolation scheme is reset and a new initial guess for the density kernel is built according to COREHAM_DENSKERN_GUESS.
MIX_DKN_TYPETextType of mixing used to build new guesses for the density kernel
MIX_LOCAL_LENGTHPhysicalCharacteristic length of the mixing scheme
MIX_LOCAL_SMEARPhysicalSmearing length of the mixing scheme
MIX_NGWFS_INIT_NUMIntegerLength of the initialization phase for the NGWFs.
MIX_NGWFS_INIT_TYPETextSpecifies the mixing scheme used during the initialisation phase for the NGWFs.
MIX_NGWFS_NUMIntegerNumber of independent coefficients used to build new guesses for the NGWFs
MIX_NGWFS_RESETIntegerEvery N MD steps, the NGWFs mixing/extrapolation scheme is reset and a new initial guess for the NGWFs is built according to SPECIES_ATOMIC_SET.
MIX_NGWFS_TYPETextType of mixing used to build new guesses for the NGWFs.
NBO_AOPNAO_SCHEMETextThe AO to PNAO scheme to use.
NBO_INIT_LCLOWDINLogicalPerforms atom-local Lowdin orthogonalisation on NGWFs as the first step before constructing NAOs.
NBO_PNAO_ANALYSISLogicalPerform s/p/d/f analysis on the PNAOs (analogous to NGWF_ANALYSIS).
NBO_SCALE_DMLogicalScales partial density matrix output to seedname_nao_nbo.47 in order to achieve charge integrality.
NBO_SCALE_SPINLogicalScales alpha and beta spins independently to integral charge when partial matrices are printed and NBO_SCALE_DM = T.
NBO_WRITE_LCLOWDINLogicalWrites full matrices (all atoms) in the atom-local Lowdin-orthogonalized basis to FILE.47
NGWF_CG_MAX_STEPRealMaximum length of trial step for NGWF optimisation line search.
NGWF_CG_ROTATELogicalRotate density kernel to the new NGWF representation after CG update. In EDFT calculations, it also rotates the eigenvectors.
NGWF_CG_TYPETextVariant of conjugate gradient algorithm to use for NGWF optimisation
NGWF_HALORealHalo width for NGWF radii in bohr
NONSC_FORCESLogicalCalculate residual non self-consistent forces
OCC_MIXRealMixing fraction of occupancy preconditioned NGWF gradient
ODD_PSINC_GRIDLogicalForce and odd number of points in the simulation cell psinc grid
OLD_LNVLogicalUse legacy algorithm for backwards compatibility
OPENBC_PSPOT_FINETUNE_ALPHARealControls the alpha parameter used in the calculation of open-BC local pseudopotential
OPENBC_PSPOT_FINETUNE_FIntegerControls the f parameter used in the calculation of open-BC local pseudopotential
OPENBC_PSPOT_FINETUNE_NPTSXIntegerControls the npts_x parameter used in the calculation of open-BC local pseudopotential
OVLP_FOR_NONLOCALLogicalUse overlap sparsity pattern for nonlocal pseudopotential matrix
PBC_CORRECTION_CUTOFFPhysicalTurn on Martyna-Tuckerman correction to the effects of periodic boundary conditions, with a specified dimensionless cutoff.
POLARISATION_SIMCELL_CALCULATEBooleanPerform calculation of polarisation in a properties calculation.
PPD_NPOINTSTextPPD size in grid points
PRECOND_REALLogicalApply kinetic energy preconditioning in real space
PRECOND_RECIPLogicalApply kinetic energy preconditioning in reciprocal space
PRECOND_SCHEMETextSpecify scheme for kinetic energy preconditioning
PRINT_QCLogicalPrint calculation summary for quality control testing
PROJECTORS_PRECALCULATELogicalWhether to pre-evaluate projectors in FFTboxes
PSINC_SPACINGTextPsinc grid spacing in bohr
R_PRECONDPhysicalRadial cutoff for real-space preconditioning
SMOOTH_PROJECTORSRealHalfwidth of Gaussian filter for smoothing non-local projectors in bohr
THREADS_PER_FFTBOXIntegerNumber of nested threads used for FFT box operations.
TSSEARCH_CG_MAX_ITERIntegerMaximum number of transition state search conjugate gradients iterations
TSSEARCH_QST_MAX_ITERIntegerMaximum number of transition state search QST iterations
TURN_OFF_EWALDBooleanElides the calculation of Ewald energy and force terms in the calculation.
USE_SPACE_FILLING_CURVELogicalDistribute atoms according to a space-filling curve
USE_SPH_HARM_ROTBooleanManually activate the sph_harm_rotation (spherical harmonic rotation) module.
VDW_DCOEFFRealOverrides the damping constant associated with a damping function.
VDW_PARAMSBlockOverride the default parameters of the dispersion damping functions.
ZERO_TOTAL_FORCELogicalSubtract average ionic force from all forces to make the total ionic force zero

BSUNFLD_KPOINT_PATH

Syntax: BSUNFLD_KPOINT_PATH [Block]
Syntax:

%BLOCK BSUNFLD_KPOINT_PATH
k1x k1y k1z
k2x k2y k2z
. . .
kNx kNy kNz
%ENDBLOCK BSUNFLD_KPOINT_PATH

Description: K-point path for bandstructure unfolding calculation.
Default Value:
Example:

%block bsunfld_kpoint_path
0.0 0.0 0.0
0.0 0.0 0.5
%endblock bsunfld_kpoint_path

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BSUNFLD_TRANSFORMATION

Syntax: BSUNFLD_TRANSFORMATION [Block]
Syntax:

%BLOCK BSUNFLD_TRANSFORMATION
S11 S12 S12
S21 S22 S23
S31 S32 S33
%ENDBLOCK BSUNFLD_TRANSFORMATION

Description: Transformation matrix (flattened) between primitive-cell and supercell lattice vectors when unfolding bandstructure
Default Value:
Example:

%block bsunfld_transformation
5 0 0
0 5 0
0 0 5
%endblock bsunfld_transformation

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BS_KPOINT_PATH

Syntax: BS_KPOINT_PATH [Block]
Syntax:

%BLOCK BS_KPOINT_PATH
k1x k1y k1z
k2x k2y k2z
. . .
kNx kNy kNz
%ENDBLOCK BS_KPOINT_PATH

Description: K-point path for bandstructure calculation.
Default Value:
Example:

%block bs_kpoint_path
0.0 0.0 0.0
0.0 0.0 0.5
%endblock bs_kpoint_path

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BS_KPOINT_PATH_SPACING

Syntax: BS_KPOINT_PATH_SPACING [Physical]
Description: K-point spacing along the bandstructure path.
Default Value:

0.1889727 "1/bohr"

Example: bs_kpoint_path_spacing 0.004 "1/bohr"
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BS_METHOD

Syntax: BS_METHOD [Integer]
Description: The method to use for the calculation of band structures - either the tight-binding style method or the k.p perturbation theory style method.
Default Value:

TB

Example: bs_method kp
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BS_NUM_EIGENVALUES

Syntax: BS_NUM_EIGENVALUES [Integer]
Description: Number of energy and occupancy eigenvalues to print below and above the Fermi level from a bandstructure calculation. If left as default all eigenvalues (2 x number of occupied states) will be printed.
Default Value:

-1; all eigenvalues

Example: bs_num_eigenvalues 10
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CDFT_ATOM_CHARGE

Syntax: CDFT_ATOM_CHARGE [Logical]
Description: Activate atom charge-constrained-DFT mode. This mode is incompatible with any other cDFT-mode.
Default Value:

False

Example: cdft_atom_charge T
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CDFT_ATOM_SPIN

Syntax: CDFT_ATOM_SPIN [Logical]
Description: Activate atom magnetic-moment-constrained-DFT mode. This mode is incompatible with any other cDFT-mode.
Default Value:

False

Example: cdft_atom_spin T
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CDFT_CG_MAX

Syntax: CDFT_CG_MAX [Real]
Description: Specifies the maximum number of constraining potential (Uq/s) conjugate gradient iterations between resets.
Default Value:

Number of independent Uq/s for CDFT_GURU = F

Example: cdft_cg_max 1
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CDFT_CG_MAX_STEP

Syntax: CDFT_CG_MAX_STEP [Real]
Description: Maximum length of trial step for the constraining potential (Uq/s) optimisation line search.
Default Value:

50.0

Example: cdft_cg_max_step 10.0
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CDFT_CG_THRESHOLD

Syntax: CDFT_CG_THRESHOLD [Real]
Description: Specifies the convergence threshold for the RMS gradient of the constraining potentials (Uq/s).
Default Value:

1.0E-3

Example: cdft_cg_threshold 0.01
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CDFT_CG_TYPE

Syntax: CDFT_CG_TYPE [Text]
Description: Specifies the variant of the conjugate gradients algorithm used for the optimization of the constraining potentials (Uq/s), currently either NGWF_FLETCHER for Fletcher-Reeves or NGWF_POLAK for Polak-Ribiere.
Default Value:

NGWF_FLETCHER

Example: cdft_cg_type NGWF_POLAK
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CDFT_CHARGE_ACCEPTOR_TARGET

Syntax: CDFT_CHARGE_ACCEPTOR_TARGET [Real]
Description: Targeted acceptor-group electron population for acceptor-group charge-constrained-DFT mode [CDFT_GROUP_CHARGE_ACCEPTOR = T].
Default Value:

0

Example: cdft_charge_acceptor_target 17
Example: ; Constrain Nup+Ndown=17 e in subspace.
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CDFT_CHARGE_DONOR_TARGET

Syntax: CDFT_CHARGE_DONOR_TARGET [Real]
Description: Targeted donor-group electron population for donor-group charge-constrained-DFT mode [CDFT_GROUP_CHARGE_DONOR = T]
Default Value:

0

Example: cdft_charge_donor_target 17
Example: ; Constrain Nup+Ndown=17 e in subspace.
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CDFT_CONTINUATION

Syntax: CDFT_CONTINUATION [Logical]
Description: Continue a constraining potential (Uq/s) optimisation from a previous run using the .cdft file with the latest cDFT-potentials. CDFT_CONTINUATION = T allows also to perform single-point cDFT runs (MAXIT_CDFT_U_CG = 0) reading atom-specific constraining potentials from .cdft file (instead of species-specific ones from the CONSTRAINED_DFT block). For CDFT_CONTINUATION = T, the constraining potentials (Uq/s) are read from the .cdft file no matter the setting of CDFT_GURU.
Default Value:

False

Example: cdft_continuation T
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CDFT_ELEC_ENERGY_TOL

Syntax: CDFT_ELEC_ENERGY_TOL [Value] [Unit]
Description: Tolerance on energy change per atom during CDFT optimisation. If negative, the option is deactivated.
Default Value:

-0.0001 hartree

Example: cdft_elec_energy_tol 0.01 hartree
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CDFT_GROUP_CHARGE_ACCEPTOR

Syntax: CDFT_GROUP_CHARGE_ACCEPTOR [Logical]
Description: Activate acceptor-group charge-constrained-DFT mode. This mode is compatible with CDFT_GROUP_CHARGE_DONOR and CDFT_GROUP_SPIN_ACCEPTOR/CDFT_GROUP_SPIN_DONOR cDFT-modes, and incompatible with CDFT_ATOM_CHARGE/CDFT_ATOM_SPIN and CDFT_GROUP_CHARGE_DIFF/CDFT_GROUP_SPIN_DIFF modes.
Default Value:

False

Example: cdft_group_charge_acceptor T
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CDFT_GROUP_CHARGE_DIFF

Syntax: CDFT_GROUP_CHARGE_DIFF [Logical]
Description: Activate group charge-difference constrained-DFT mode. This mode is compatible with CDFT_GROUP_SPIN_DIFF cDFT mode only. Thus, it is incompatible with any other CDFT_ATOM_CHARGE/SPIN and CDFT_GROUP_CHARGE/SPIN_ACCEPTOR/DONOR cDFT modes.
Default Value:

False

Example: cdft_group_charge_diff T
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CDFT_GROUP_CHARGE_DIFF_TARGET

Syntax: CDFT_GROUP_CHARGE_DIFF_TARGET [Real]
Description: Targeted electron population difference between acceptor and donor group for group-charge-difference constrained-DFT mode [CDFT_GROUP_CHARGE_DIFF =T].
Default Value:

0

Example: cdft_group_charge_diff_target 2
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CDFT_GROUP_CHARGE_DONOR

Syntax: CDFT_GROUP_CHARGE_DONOR [Logical]
Description: Activate donor-group charge-constrained-DFT mode. This mode is compatible with CDFT_GROUP_CHARGE_ACCEPTOR and CDFT_GROUP_SPIN_ACCEPTOR/CDFT_GROUP_SPIN_DONOR cDFT-modes, and incompatible with CDFT_ATOM_CHARGE/CDFT_ATOM_SPIN and CDFT_GROUP_CHARGE_DIFF/CDFT_GROUP_SPIN_DIFF modes.
Default Value:

False

Example: cdft_group_charge_donor T
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CDFT_GROUP_CHARGE_DOWN_ONLY

Syntax: CDFT_GROUP_CHARGE_DOWN_ONLY [Logical]
Description: Constrain only SPIN-DOWN channel in CDFT_GROUP_CHARGE_ACCEPTOR, CDFT_GROUP_CHARGE_DONOR and CDFT_GROUP_CHARGE_DIFF modes. To avoid disaster, make sure the specified CDFT_CHARGE_ACCEPTOR/DONOR_TARGET or CDFT_CHARGE_DIFF_TARGET keywords are consistent with the fact only one spin channel is being constrained. This functionality is NOT compatible with CDFT_GROUP_CHARGE_UP_ONLY, CDFT_ATOM_CHARGE/SPIN, and CDFT_GROUP_SPIN_ACCEPTOR/DONOR and CDFT_GROUP_SPIN_DIFF cDFT modes.
Default Value:

False

Example: cdft_group_charge_down_only T
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CDFT_GROUP_CHARGE_UP_ONLY

Syntax: CDFT_GROUP_CHARGE_UP_ONLY [Logical]
Description: Constrain only SPIN-UP channel in CDFT_GROUP_CHARGE_ACCEPTOR, CDFT_GROUP_CHARGE_DONOR and CDFT_GROUP_CHARGE_DIFF modes. To avoid disaster, make sure the specified CDFT_CHARGE_ACCEPTOR/DONOR_TARGET or CDFT_CHARGE_DIFF_TARGET keywords are consistent with the fact only one spin channel is being constrained. This functionality is NOT compatible with CDFT_GROUP_CHARGE_UP_ONLY, CDFT_ATOM_CHARGE/SPIN, and CDFT_GROUP_SPIN_ACCEPTOR/DONOR and CDFT_GROUP_SPIN_DIFF cDFT modes.
Default Value:

False

Example: cdft_group_charge_up_only T
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CDFT_GROUP_SPIN_ACCEPTOR

Syntax: CDFT_GROUP_SPIN_ACCEPTOR [Logical]
Description: Activate acceptor-group magnetic-moment-constrained-DFT mode. This mode is compatible with CDFT_GROUP_SPIN_DONOR and CDFT_GROUP_CHARGE_ACCEPTOR/CDFT_GROUP_CHARGE_DONOR cDFT-modes, and incompatible with CDFT_ATOM_CHARGE/CDFT_ATOM_SPIN and CDFT_GROUP_CHARGE_DIFF/CDFT_GROUP_SPIN_DIFF modes.
Default Value:

False

Example: cdft_group_spin_acceptor T
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CDFT_GROUP_SPIN_DIFF

Syntax: CDFT_GROUP_SPIN_DIFF [Logical]
Description: Activate group magnetic-moment-difference constrained-DFT mode. This mode is compatible with CDFT_GROUP_CHARGE_DIFF cDFT mode only. Thus, it is incompatible with any other CDFT_ATOM_CHARGE/SPIN and CDFT_GROUP_CHARGE/SPIN_ACCEPTOR/DONOR cDFT modes.
Default Value:

False

Example: cdft_group_spin_diff T
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CDFT_GROUP_SPIN_DIFF_TARGET

Syntax: CDFT_GROUP_SPIN_DIFF_TARGET [Real]
Description: Targeted magnetic-moment difference between acceptor and donor group for group-magnetic-moment-difference constrained-DFT mode [CDFT_GROUP_SPIN_DIFF =T].
Default Value:

0

Example: cdft_group_spin_diff_target 2
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CDFT_GROUP_SPIN_DONOR

Syntax: CDFT_GROUP_SPIN_DONOR [Logical]
Description: Activate donor-group magnetic-moment-constrained-DFT mode. This mode is compatible with CDFT_GROUP_SPIN_ACCEPTOR and CDFT_GROUP_CHARGE_ACCEPTOR/CDFT_GROUP_CHARGE_DONOR cDFT-modes, and incompatible with CDFT_ATOM_CHARGE/CDFT_ATOM_SPIN and CDFT_GROUP_CHARGE_DIFF/CDFT_GROUP_SPIN_DIFF modes.
Default Value:

False

Example: cdft_group_spin_donor T
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CDFT_GURU

Syntax: CDFT_GURU [Logical]
Description: Tell ONETEP you are a cDFT-expert and prevent it from initialising the active |Uq/s| to the failsafe value of 1 eV, overwriting the values entered in the CONSTRAINED_DFT (Uq/s) block.
Default Value:

False

Example: cdft_guru T
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CDFT_HUBBARD

Syntax: CDFT_HUBBARD [Logical]
Description: Activate the constrained-DFT+U functionality. It requires specifications of a positive value for the Hubbard correction (Uh) in the CONSTRAINED_DFT Block.
Default Value:

False

Example: cdft_hubbard T
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CDFT_MAX_GRAD

Syntax: CDFT_MAX_GRAD [Real]
Description: Specifies the convergence threshold for the maximum value of the constraining-potential (Uq/s) gradient at any cDFT-site.
Default Value:

1.0E-3

Example: cdft_max_grad 0.01
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CDFT_MULTI_PROJ

Syntax: CDFT_MULTI_PROJ [Logical]
Description: Activate the “as many cDFT-projectors as NGWFs” cDFT-mode. In this mode, the number of cDFT-projectors for a given cDFT-atom equals the number of NWGFs for that atom as specified in the SPECIES block. Both the cDFT-projectors and the NGWFs are localised within spheres of the same radius. When activated, this mode overwrites the L-projectors and Z-projectors settings in the CONSTRAINED_DFT block, and the cDFT-projectors are built according to the settings in the SPECIES_ATOMIC_SET block for that atom=cDFT-site.
Default Value:

False

Example: cdft_multi_proj T
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CDFT_PRINT_ALL_OCC

Syntax: CDFT_PRINT_ALL_OCC [Logical]
Description: Print detailed information of occupancies for al the cDFT-sites, for OUTPUT_DETAIL = VERBOSE.
Default Value:

False

Example: cdft_print_all_occ T
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CDFT_READ_PROJ

Syntax: CDFT_READ_PROJ [Logical]
Description: Read cDFT-projectors from .tightbox_hub_proj file. Activation of this keyword overwrites any Z-projector setting in the CONSTRAINED_DFT block. It also makes not necessary to set HUBBARD_PROJ_MIXING < 0 to have task=HUBBARDSCF run with file-read projectors.
Default Value:

False

Example: cdft_read_proj T
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CDFT_SPIN_ACCEPTOR_TARGET

Syntax: CDFT_SPIN_ACCEPTOR_TARGET [Real]
Description: Targeted group magnetic-moment for acceptor-group magnetic-moment constrained-DFT mode [CDFT_GROUP_SPIN_ACCEPTOR = T].
Default Value:

0

Example: cdft_spin_acceptor_target -2
Example: ; Constrain Nup-Ndown=-2 e in subspace.
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CDFT_SPIN_DONOR_TARGET

Syntax: CDFT_SPIN_DONOR_TARGET [Real]
Description: Targeted group magnetic-moment for donor-group magnetic-moment constrained-DFT mode [CDFT_GROUP_SPIN_DONOR = T].
Default Value:

0

Example: cdft_spin_donor_target -2
Example: ; Constrain Nup-Ndown=-2 e in subspace.
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CDFT_TRIAL_LENGTH

Syntax: CDFT_TRIAL_LENGTH [Real]
Description: Specifies initial trial length for first step of constraining-potential (Uq/s) conjugate gradients optimisation.
Default Value:

0.1

Example: cdft_trial_length 1.0
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CHARGE

Syntax: CHARGE [Integer]
Description: Specifies the total charge of the system in units of the proton charge i.e. a positive charge corresponds to a system deficient of electrons.
Default Value:

0 ; charge neutral

Example: charge +1
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CHECK_ATOMS

Syntax: CHECK_ATOMS [Logical]
Description: Perform a check on the atomic positions to ensure that no two atoms are unphysically close.
Default Value:

True

Example: check_atoms F
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CI_CDFT

Syntax: CI_CDFT [Logical]
Description: Perform a Configuration Interaction calculation based on constrained-DFT configurations.
Default Value:

False

Example: ci_cdft T
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CI_CDFT_NUM_CONF

Syntax: CI_CDFT_NUM_CONF [Integer]
Description: Specifies the number of constrained-DFT configuration available for a CI_CDFT = T simulation.
Default Value:

0

Example: ci_cdft_num_conf 4
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CLASSICAL_INFO

Syntax: CLASSICAL_INFO [Block]
Syntax:

%BLOCK CLASSICAL_INFO
S1 R1x R1y R1z Ch1
S2 R2x R2y R2z Ch2
. . . . .
. . . . .
SN RNx RNy RNz ChN
%ENDBLOCK CLASSICAL_INFO

Description: Introduce classical point charges in the system (no NGWFs are associated to them). The classical point charges interact via classical Coulomb interactions with the atoms and the rest of point charges. Specifies the atomic positions as Cartesian coordinates in atomic units (a0). In the above syntax, Si denotes the species of the charge (max 4 characters),Ri its position vector and Chi the charge in atomic units.
Default Value:
Example:

%block classical_info
O 19.7 21.8 22.6 -0.3
H 17.6 22.1 22.6 0.12
H 20.7 23.6 22.6 0.17
%endblock classical_info

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COMMS_GROUP_SIZE

Syntax: COMMS_GROUP_SIZE [Text]
Description: To reduce comms bandwidth in an MPI job, groups of MPI processes are specified which pre-share matrix and cell-grid data between themselves before communications-heavy routines, such as sparse matrix algebra and cell extract/deposit routines. This integer specifies the size of these groups. This might often be most advantageously be set to the size of a physical "node" of a the parallel computer (ie the number of processes which share each chunk of physical memory).
Default Value:

The largest factor that is smaller than (or equal to) the square root of the total number of MPI processes (nodes).

Example: comms_group_size 16
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COND_CALC_MAX_EIGEN

Syntax: COND_CALC_MAX_EIGEN [Logical]
Description: Calculate maximum conduction Hamiltonian eigenvalue at the start of each NGWF CG optimisation step, for use in updating the shift for the projected conduction Hamiltonian.
Default Value:

True

Example: cond_calc_max_eigen
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COND_CALC_OPTICAL_SPECTRA

Syntax: COND_CALC_OPTICAL_SPECTRA [Logical]
Description: Calculate the optical matrix elements in the momentum representation, required for extended systems and molecules with large NGWF radii. If false the position representation is instead used.
Default Value:

False

Example: cond_calc_optical_spectra T
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COND_ENERGY_GAP

Syntax: COND_ENERGY_GAP [Physical]
Description: Energy gap required above states that will be optimised during a conduction NGWF optimisation. The number of states may be increased until such a gap is found.
Default Value:

0.001 hartree

Example: cond_energy_gap 0.1 eV
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COND_ENERGY_RANGE

Syntax: COND_ENERGY_RANGE [Physical]
Description: Energy range of states that will be optimised during a conduction NGWF optimisation. This is counted as the number of states measured from the highest occupied molecular orbital (HOMO).

Negative values mean this range is not used in determining the occupancy of the conduction kernel.
Default Value:

-1.0 hartree

Example: cond_energy_range 5.0 eV
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COND_FIXED_SHIFT

Description: Keep shift for projected conduction Hamiltonian constant in COND task
Default Value:
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COND_INIT_SHIFT

Syntax: COND_INIT_SHIFT [Physical]
Description: Initial shifting factor for projected conduction Hamiltonian, added to each eigenvalue.
Default Value:

0.0 hartree

Example: cond_init_shift 0.1 "hartree"
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COND_KERNEL_CUTOFF

Syntax: COND_KERNEL_CUTOFF [Physical]
Description: Specifies the conduction density kernel spatial cutoff in atomic units (a0). Matrix elements are only included if the corresponding conduction NGWF centres are closer than this distance.
Default Value:

1000.0 bohr; i.e. effectively infinite

Example: cond_kernel_cutoff 25.0 "bohr"
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COND_MAXIT_LNV

Syntax: COND_MAXIT_LNV [Integer]
Description: Max number of LNV iterations during conduction NGWF optimisation.
Default Value:

10

Example: cond_maxit_lnv 20
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COND_MINIT_LNV

Syntax: COND_MINIT_LNV [Integer]
Description: Minimum number of LNV iterations during conduction NGWF optimisation.
Default Value:

10

Example: cond_minit_lnv 15
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COND_NUM_EXTRA_ITS

Syntax: COND_NUM_EXTRA_ITS [Integer]
Description: The number of iterations for which the conduction NGWFs are optimised for COND_NUM_STATES + COND_NUM_EXTRA_STATES during an initial pre-optimisation stage to help avoid becoming trapped in local minima. If COND_NUM_EXTRA_STATES = 0 this is ignored.
Default Value:

0

Example: cond_num_extra_its 5
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COND_NUM_EXTRA_STATES

Syntax: COND_NUM_EXTRA_STATES [Integer]
Description: The number of additional conduction states to be optimised during an initial pre-optimisation stage to help avoid becoming trapped in local minima. This follows the same guidelines as COND_NUM_STATES . See also COND_NUM_EXTRA_ITS.
Default Value:

0

Example: cond_num_extra_states 10
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COND_NUM_STATES

Syntax: COND_NUM_STATES [Integer]
Description: The number of conduction states to be optimised (spin up + down). For non-spin-polarised calculations, this should be an even number.
Default Value:

Equal to the number of valence electrons

Example: cond_num_states 20
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COND_PLOT_JOINT_ORBITALS

Syntax: COND_PLOT_JOINT_ORBITALS [Logical]
Description: Plot orbitals in the joint valence-conduction NGWF basis following a conduction calculation. Applies to HOMO_PLOT and LUMO_PLOT. See also COND_PLOT_VC_ORBITALS.
Default Value:

True

Example: cond_plot_joint_orbitals F
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COND_PLOT_VC_ORBITALS

Description: Plot orbitals in separate val cond bases following COND task
Default Value:
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COND_READ_DENSKERN

Syntax: COND_READ_DENSKERN [Logical]
Description: Read in the conduction density kernel from disk. If the input filename is rootname.dat then the conduction density kernel filename is rootname.dkn_cond.
Default Value:

False (True if TASK = PROPERTIES_COND)

Example: cond_read_denskern T
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COND_READ_TIGHTBOX_NGWFS

Syntax: COND_READ_TIGHTBOX_NGWFS [Logical]
Description: Read in the conduction NGWFs from disk. If the input filename is rootname.dat then the conduction NGWFs filename is rootname.tightbox_ngwfs_cond.
Default Value:

False (True if TASK = PROPERTIES_COND)

Example: cond_read_tightbox_ngwfs T
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COND_SHIFT_BUFFER

Syntax: COND_SHIFT_BUFFER [Physical]
Description: Additional buffer to add to the highest calculated eigenvalue when updating the shift for the projected conduction Hamiltonian.
Default Value:

0.1 hartree

Example: cond_shift_buffer 0.5 "hartree"
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COND_SPEC_CALC_MOM_MAT_ELS

Syntax: COND_SPEC_CALC_MOM_MAT_ELS [Logical]
Description: Calculate the optical matrix elements in the momentum representation, required for extended systems and molecules with large NGWF radii. If false the position representation is instead used.
Default Value:

True

Example: cond_spec_calc_mom_mat_els F
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COND_SPEC_CALC_NONLOC_COMM

Syntax: COND_SPEC_CALC_NONLOC_COMM [Logical]
Description: Calculate the commutator between the nonlocal potential and the position operator, required for accurate calculation of optical absorption spectra when COND_SPEC_CALC_MOM_MAT_ELS = true.
Default Value:

True

Example: cond_spec_calc_nonloc_comm F
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COND_SPEC_CONT_DERIV

Syntax: COND_SPEC_CONT_DERIV [Logical]
Description: Calculate the commutator between the nonlocal potential and the position operator (when COND_SPEC_CALC_NONLOC_COMM : true) using a continuous derivative in k-space. If false a finite difference is instead used in k-space.
Default Value:

True

Example: cond_spec_cont_deriv F
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COND_SPEC_NONLOC_COMM_SHIFT

Syntax: COND_SPEC_NONLOC_COMM_SHIFT [Real]
Description: Finite difference shift used for calculating the commutator between the nonlocal potential and the position operator if calculating using finite differences (i.e. when COND_SPEC_CONT_DERIV : false).
Default Value:

0.0001

Example: cond_spec_nonloc_comm_shift 0.00001
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CONSTANT_EFIELD

Syntax: CONSTANT_EFIELD [Text]
Description: Specifies a constant electric field to apply to the system in terms of Cartesian vector components in atomic units Ha/(e a0).
Default Value:

0.0 0.0 0.0 ; zero field

Example: constant_efield 1.0e-3 0.0 0.0
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CONSTRAINED_DFT

Syntax:

%BLOCK CONSTRAINED_DFT
S1 L1 Z1 Uh1(UP) Uq1(DOWN) Us1 N1(UP) N1(DOWN) [N1(UP)-N1(DOWN)]
S2 L2 Z2 Uh2(UP) Uq2(DOWN) Us2 N2(UP) N2(DOWN) [N2(UP)-N2(DOWN)]
. . . . .
. . . . .
SM LM ZM UhM(UP) UqM(DOWN) UsM NM(UP) NM(DOWN) [NM(UP)-NM(DOWN)]
%ENDBLOCK CONSTRAINED_DFT

Description: Manages constrained-DFT simulations. Provided CDFT_MULTI_PROJ = F, for species S and subspace of angular momentum channel L (with principal quantum number n=L+1) we apply charge spin-specific [Uq(UP), Uq(DOWN)] or magnetic-moment-specific (Us) constraining potentials (in eV). For CDFT_ATOM_CHARGE = T, N(UP) and N(DOWN) indicate the targeted e-population for spin-channel UP and DOWN, respectively. For CDFT_ATOM_SPIN = T, [N1(UP)-N1(DOWN)] indicates the targeted e-population difference (i.e. local magnetic moment). Uh indicates the optional Hubbard parameter (U, eV) to be
applied for CDFT_HUBBARD = T. An effective nuclear charge Z defines the hydrogenic orbitals spanning the subspace unless a negative value is given, e.g., Z=-10, in which case the NGWFs initial guess orbitals (numerical atomic orbitals) are used. Depending on the activated cDFT-mode, different columns of the block are used. These are:
  • S, L, Z, (Uh), Uq(UP), Uq(DOWN), N(UP), N(DOWN) for CDFT_ATOM_CHARGE = T
  • S, L, Z, (Uh), Us, [N(UP)-N(DOWN)] for CDFT_ATOM_SPIN = T
  • S, L, Z, (Uh), Uq(UP), Uq(DOWN) for CDFT_GROUP_CHARGE_ACCEPTOR = T, CDFT_GROUP_CHARGE_DONOR = T, or CDFT_GROUP_CHARGE_DIFF = T. In this case, Uq(UP) must be equal to Uq(DOWN). Acceptor and donor atoms are differentiated by mean of negative [Uq(UP/DOWN)<0] and positive [Uq(UP/DOWN)>0] constraining-potentials, respectively. Setting Uq=0 will result in the given cDFT-atom being excluded from the list of the atoms in a given CDFT_GROUP_CHARGE_DONOR/ACCEPTOR/DIFF group.
  • S, L, Z, (Uh), and Us for CDFT_GROUP_SPIN_ACCEPTOR = T, CDFT_GROUP_SPIN_DONOR = T, or CDFT_GROUP_SPIN_DIFF = T. In this case, Acceptor and donor atoms are differentiated by mean of negative (Us<0) and positive (Us>0) constraining-potentials, respectively. Setting Us=0 will result in the given cDFT-atom being excluded from the list of the atoms in a given CDFT_GROUP_SPIN_DONOR/ACCEPTOR/DIFF group.
  • For more clarifying information please consult cDFT_keywords.pdf.
  • Default Value:
    Example:

    %BLOCK CONSTRAINED_DFT
    # L Z Uh Uq(UP) Uq(DOWN) Us N(UP) N(DOWN) [N(UP)-N(DOWN)]
    N1 1 -5. 0.0 11.0 11.0 0.0 2.3 1.3 0.
    N2 1 -5. 0.0 -26.0 -26.0 0.0 2.7 2.7 0.
    %ENDBLOCK CONSTRAINED_DFT

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    COREHAM_DENSKERN_GUESS

    Syntax: COREHAM_DENSKERN_GUESS [Logical]
    Description: Generate an initial guess for the density kernel using a Hamiltonian generated by simple atomic screening of the pseudopotential. The density kernel may be obtained by the Palser-Manolopoulos algorithm or direct diagonalization. If false, a simple diagonal approximation is used for the density kernel.
    Default Value:

    True

    Example: coreham_denskern_guess F
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    COULOMB_CUTOFF_LENGTH

    Syntax: COULOMB_CUTOFF_LENGTH [Value] [Unit]
    Description: Cutoff Coulomb only. Chooses the length of either (a) the cylinder on which the Coulomb interaction is truncated, in the case of a cylindrical cutoff, or (b) the slab on which the Coulomb interaction is truncated, in the case of a slab cutoff.
    Default Value:

    0 bohr

    Example: coulomb_cutoff_length 100 bohr
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    COULOMB_CUTOFF_RADIUS

    Syntax: COULOMB_CUTOFF_RADIUS [Value] [Unit]
    Description: Cutoff Coulomb only. Chooses the radius of the sphere, cylinder or wire on which the Coulomb interaction is truncated.
    Default Value:

    0 bohr

    Example: coulomb_cutoff_radius 100 bohr
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    COULOMB_CUTOFF_TYPE

    Syntax: COULOMB_CUTOFF_TYPE [Text]
    Description: Activates Cutoff Coulomb interactions, and chooses which type of cutoff to apply. Allowed values are: NONE, SPHERE, CYLINDER, SLAB, WIRE.
    Default Value:

    NONE

    Example: coulomb_cutoff_type SPHERE
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    COULOMB_CUTOFF_WRITE_INT

    Syntax: COULOMB_CUTOFF_WRITE_INT [Value]
    Description: Writes a scalarfield plot of the Cutoff Coulomb interaction for the chosen geometry and cutoff type. Plots .grd or .cube according to the options chosen for GRD_FORMAT and CUBE_FORMAT
    Default Value:

    F

    Example: coulomb_cutoff_write_int T
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    CUBE_FORMAT

    Syntax: CUBE_FORMAT [Logical]
    Description: Output volumetric data (e.g. charge density, potential, NGWFs, canonical orbitals) in cube format . This can be visualized using free software such as gOpenMol , MOLEKEL and XCrySDen .
    Default Value:

    True

    Example: cube_format T
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    CUTOFF_ENERGY

    Syntax: CUTOFF_ENERGY [Value] [Unit]
    Description: Chooses the psinc basis set to correspond as closely as possible to a plane-wave basis with this cutoff energy. See section 3 of Skylariset al.,J. Phys.: Condens. Matter17, 5757 (2005) for more details.
    Default Value:

    20 Ha

    Example: cutoff_energy 500 eV
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    DBL_GRID_SCALE

    Syntax: DBL_GRID_SCALE [Real]
    Description: Ratio of charge density / potential working grid to standard grid (1 or 2 only).
    Default Value:

    2.0

    Example: dbl_grid_scale 1.0
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    DDEC_CALCULATE

    Syntax: ddec_calculate [Logical]
    Description: Activate Density Derived Electrostatic and Chemical analysis routines.
    Default Value:

    False

    Example: ddec_calculate T
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    DDEC_CLASSICAL_HIRSHFELD

    Syntax: ddec_classical_hirshfeld [Logical]
    Description: Output results from classical Hirshfeld partitioning, which are the atomic charges from the 1st iteration of DDEC. Reference densities must be initialised as neutral atomic densities using the keyword 'ddec_refdens_init: T'
    Default Value:

    False

    Example: ddec_classical_hirshfeld T
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    DDEC_CONV_THRESH

    Syntax: ddec_conv_thresh [Value] [Unit]
    Description: Threshold for DDEC charges to be considered converged.
    Default Value:

    1e-5 e

    Example: ddec_conv_thresh 1e-7 e
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    DDEC_CORE_MAXIT

    Syntax: ddec_core_maxit [Value]
    Description: Maximum number of DDEC core iterations.
    Default Value:

    2000

    Example: ddec_core_maxit 4000
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    DDEC_IH_FRACTION

    Syntax: ddec_IH_fraction [Value]
    Description: Fraction of reference ion weighting used in DDEC partitioning.
    Default Value:

    3/14

    Example: ddec_IH_fraction 0.5
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    DDEC_IH_IONIC_RANGE

    Syntax: ddec_ih_ionic_range [Value]
    Description: Range of charges (positive or negative with respect to the neutral atom) to be generated for each ionic species as ionic reference densities. DDEC calculation will exit if the charge on any atom exceeds this range.
    Default Value:

    2

    Example: ddec_ih_ionic_range 4
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    DDEC_INTERP_RAD_DENS

    Syntax: ddec_interp_rad_dens [Logical]
    Description: Trilinear postprocessing interpolation of converged DDEC AIM densities for a smoother profile. Does not affect calculation results, only the output density profiles.
    Default Value:

    False

    Example: ddec_interp_rad_dens T
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    DDEC_MAXIT

    Syntax: ddec_maxit [Value] [Unit]
    Description: Maximum number of DDEC iterations.
    Default Value:

    2000

    Example: ddec_maxit 4000
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    DDEC_MIN_SHELL_DENS

    Syntax: ddec_min_shell_dens [Value]
    Description: Minimum number of points lying in each spherical shell.
    Shells with fewer points than this will be subjected to interpolation if 'ddec_interp_rad_dens: T'.
    Default Value:

    100.0

    Example: ddec_min_shell_dens 50.0
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    DDEC_MOMENT

    Syntax: ddec_moment [Value]
    Description: Calculate DDEC AIM moment of order n. Set to positive integer n to turn on calculation.
    Default Value:

    -1

    Example: ddec_moment 5
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    DDEC_MULTIPOLE

    Syntax: ddec_multipole [Logical]
    Description: Calculate DDEC AIM dipoles and quadrupoles.
    Default Value:

    False

    Example: ddec_multipole T
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    DDEC_RAD_NPTS

    Syntax: ddec_rad_npts [Value]
    Description: Number of atom-centered shells used for spherical averaging and storing the DDEC AIM density profiles.
    Default Value:

    100

    Example: ddec_rad_npts 250
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    DDEC_RAD_RCUT

    Syntax: ddec_rad_rcut [Value] [Unit]
    Description: Radius of the largest spherical shell for DDEC analysis. Each spherical shell is spaced equally.
    Default Value:

    5.0 ang

    Example: ddec_rad_rcut 6.0 ang
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    DDEC_REFDENS_INIT

    Syntax: ddec_refdens_init [Logical]
    Description: Initialize DDEC AIM densities as neutral atom reference densities. Required for 'ddec_classical_hirshfeld'.
    Default Value:

    True

    Example: ddec_refdens_init F
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    DDEC_WRITE_RAD

    Syntax: ddec_write_rad [Logical]
    Description: Write converged AIM spherically-averaged density profiles for all atoms.
    Default Value:

    False

    Example: ddec_write_rad T
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    DDEC_ZERO_THRESHOLD

    Syntax: ddec_zero_threshold [Value]
    Description: Threshold for density on grid to be excluded in order to avoid division by zero.
    Default Value:

    1e-10

    Example: ddec_zero_threshold 1e-8
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    DELTA_E_CONV

    Syntax: DELTA_E_CONV [Logical]
    Description: When aggressive density kernel truncation is applied, the energy is not guaranteed to decrease monotonically. When DELTA_E_CONV is true, consecutive energy gains are used as an additional convergence criterion.
    Default Value:

    True (False if TASK = HUBBARDSCF)

    Example: delta_e_conv F
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    DENSE_FOE

    Syntax: DENSE_FOE [Logical]
    Description: By default the density kernel is calculated in a sparse format in FOE, even when it has no sparsity. If the user wants to apply FOE to systems of less than ~1000 atoms, then using dense matrix algebra may be beneficial.
    Default Value:

    F

    Example: dense_foe T
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    DENSE_THRESHOLD

    Syntax: DENSE_THRESHOLD [Value]
    Description: Sets the filling fraction threshold above which a section of a sparse matrix will be set to dense. Dense matrix algebra is computationally faster above filling fractions of ~10%, but higher communications bandwidth is required so higher values may degrade performance on low-bandwidth parallel architectures. Most users will not need to change this, but in some cases, a higher value than the default can reduce communications bottlenecks during sparse matrix multiplication.
    Default Value:

    0.40

    Example: dense_threshold 0.80
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    DISPERSION

    Syntax: DISPERSION [Integer]
    Description: Specifies the damping function to be used in the calculation of dispersion corrections:
    • 0 - No dispersion correction
    • 1 - Damping function from Elstner [J. Chem. Phys. 114(12), 5149-5155]
    • 2 - First damping function from Wu and Yang (I) [J. Chem. Phys. 116(2), 515-524, 2002]
    • 3 - Second damping function from Wu and Yang (II) [J. Chem. Phys. 116(2), 515-524, 2002]
    • 4 - Damping function of D2 correction of Grimme [ S. Grimme,
      J. Comput. Chem. 27(15), 1787-1799, 2006]

    See Proceedings of the Royal Society A 465(2103), 669-683 for more details.

    Default Value:

    0

    Example: dispersion 1
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    DOS_SMEAR

    Syntax: DOS_SMEAR [Value] [Unit]
    Description: Specifies the Gaussian smearing for the density of states calculatedif properties are requested. If the smearing width is negative, the density of states is not calculated.
    Default Value:

    0.1 eV

    Example: dos_smear 7 mRy
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    DO_PROPERTIES

    Syntax: DO_PROPERTIES [Logical]
    Description: Enables the calculation of properties including: charge and spin densities, electrostatic potential , Mulliken population analysis , canonical orbitals and energies and density of states.
    Default Value:

    False

    Example: do_properties T
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    DX_FORMAT

    Syntax: DX_FORMAT [Logical]
    Description: Output volumetric data (e.g. charge density, potential, NGWFs, canonical orbitals) in Open DX format. This can be visualized using free software such as OpenDX or VMD.
    Default Value:

    False

    Example: dx_format T
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    DX_FORMAT_COARSE

    Syntax: DX_FORMAT_COARSE [Logical]
    Description: Makes the .dx files (see DX_FORMAT) smaller by outputting only odd points along every axis, discarding even points. This allows for smaller output files, eliminates Gibbs ringing.
    Default Value:

    False

    Example: dx_format_coarse T
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    DX_FORMAT_DIGITS

    Syntax: DX_FORMAT_DIGITS [Integer]
    Description: Selects the number of significant digits in .dx file (see DX_FORMAT) output. This allows for smaller files if some precision can be sacrificed, or to increase output precision of need arises.
    Default Value:

    7 (that is, 1 before and 6 after the decimal point)

    Example: dx_format_digits 12
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    EDFT

    Syntax: EDFT [Logical]
    Description: Enable finite-temperature DFT calculations with the Ensemble-DFT method. Recommended for calculations on metallic systems.
    Default Value:

    F

    Example: edft T
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    EDFT_COMMUTATOR_THRES

    Syntax: EDFT_COMMUTATOR_THRES [Value] [Unit]
    Description: Tolerance threshold for the Hamiltonian-density matrix commutator during the EDFT inner loop.
    Default Value:

    1.0E-5 Hartree

    Example: edft_commutator_thres 1.0e-6
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    EDFT_ENERGY_THRES

    Syntax: EDFT_ENERGY_THRES [Value] [Unit]
    Description: Tolerance threshold for the maximum change of the total energy during two consecutive EDFT inner loop iteratrions.
    Default Value:

    1.0E-4 Hartree

    Example: edft_energy_thres 1.0e-4 eV
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    EDFT_ENTROPY_THRES

    Syntax: EDFT_ENTROPY_THRES [Value] [Unit]
    Description: Tolerance threshold for the maximum change of the total entropy during two consecutive EDFT inner loop iteratrions.
    Default Value:

    1.0E-4 Hartree

    Example: edft_entropy_thres 1.0e-5 eV
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    EDFT_EXTRA_BANDS

    Syntax: EDFT_EXTRA_BANDS [Integer]
    Description: Extra energy bands in EDFT calculations. If set to 0 or a negative number, the total number of bands is equal to the total number of NGWFs. Set to a positive integer to add more energy bands.
    Default Value:

    -1

    Example: edft_extra_bands 16
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    EDFT_FERMI_THRES

    Syntax: EDFT_FERMI_THRES [Value] [Unit]
    Description: Tolerance threshold for the maximum change of the Fermi energy during two consecutive EDFT inner loop
    Default Value:

    1.0E-3 Hartree

    Example: edft_fermi_thres 1.0e-4 eV
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    EDFT_FREE_ENERGY_THRES

    Syntax: EDFT_FREE_ENERGY_THRES [Value] [Unit]
    Description: Tolerance threshold for the maximum change of the Helmholtz free energy during two consecutive EDFT inner loop iteratrions.
    Default Value:

    1.0E-6 Hartree

    Example: edft_free_energy_thres 1.0e-4 eV
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    EDFT_INIT_MAXIT

    Syntax: EDFT_INIT_MAXIT [Integer]
    Description: Maximum number of inner loop iterations with the EDFT method to be performed at the start of the calculation, intended to solve issues with incorrect occupancy schemes after initialisation via Palser Manolopoulos.
    Default Value:

    0

    Example: edft_init_maxit 5
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    EDFT_MAXIT

    Syntax: EDFT_MAXIT [Integer]
    Description: Maximum number of inner loop iterations in calculations with the EDFT method.
    Default Value:

    10

    Example: edft_maxit 5
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    EDFT_MAX_STEP

    Syntax: EDFT_MAX_STEP [Value]
    Description: Maximum step during the EDFT inner loop line search.
    Default Value:

    1.0

    Example: edft_max_step 0.8
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    EDFT_RMS_GRADIENT_THRES

    Syntax: EDFT_RMS_GRADIENT_THRES [Value]
    Description: Tolerance threshold for the maximum occupancies RMS gradient during the EDFT inner loop.
    Default Value:

    1.0E-4

    Example: edft_rms_gradient_thres 1.0e-5
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    EDFT_ROUND_EVALS

    Syntax: EDFT_ROUND_EVALS [Integer]
    Description: Round up the energy eigenvalues to n decimal positions. It helps in calculations where there is a numerical error arising from the grid representation of the NGWFs. If set to a negative number, this directive is ignored.
    Default Value:

    -1

    Example: edft_round_evals 5
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    EDFT_SMEARING_WIDTH

    Syntax: EDFT_SMEARING_WIDTH [Value] [Unit]
    Description: Occupation smearing width in EDFT calculations, based on the Fermi-Dirac distribution.
    Default Value:

    0.003166811429 hartree

    Example: edft_smearing_width 0.2 eV
    Example: edft_smearing_width 800 K (sets the electronic temperature to 800 degree Kelvin)
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    EDFT_SPIN_FIX

    Syntax: EDFT_SPIN_FIX [Integer]
    Description: Number of NGWF CG iterations to hold the spin fixed. If negative, hold forever. (Default: -1)
    Default Value:

    -1

    Example: edft_spin_fix 4
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    EDFT_WRITE_OCC

    Syntax: EDFT_WRITE_OCC [Logical]
    Description: Write the occupancies and the energy levels on disk. If set to true, this directive will generate a .occ file.
    Default Value:

    False

    Example: edft_write_occ T
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    EIGENSOLVER_ABSTOL

    Syntax: EIGENSOLVER_ABSTOL [Value]
    Description: Indicates the precision to which the ScaLapack PDSYGVX eigensolver will resolve the eigenvalues of a matrix. Active only if ONETEP is compiled against ScaLapack. Set to a negative number to use ScaLAPACK default.
    Default Value:

    1.0E-9

    Example: eigensolver_abstol 1.0e-5
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    EIGENSOLVER_ORFAC

    Syntax: EIGENSOLVER_ORFAC [Value]
    Description: Indicates the precision to which the ScaLapack PDSYGVX eigensolver will reorthonormalise the eigenvectors of a matrix. Active only if ONETEP is compiled against ScaLapack. Set to a negative number to tell ScaLAPACK to not to perform any kind of orthonormalisation.
    Default Value:

    1.0E-4

    Example: eigensolver_abstol 1.0e-3
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    ELD_CALCULATE

    Syntax: ELD_CALCULATE [Logical]
    Description: Calculate electron localisation descriptors.
    Default Value:

    False

    Example: eld_calculate T
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    ELD_FUNCTION

    Syntax: ELD_FUNCTION [Text]
    Description: Choose which electron localisation descriptor to use during the properties calculation, either ELF or LOL.
    Default Value:

    ELF

    Example: eld_function ELF
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    ELEC_CG_MAX

    Syntax: ELEC_CG_MAX [Integer]
    Description: Specifies the maximum number of NGWF conjugate gradients iterations between resets.
    Default Value:

    3

    Example: elec_cg_max 0 ; steepest descents
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    ELEC_ENERGY_TOL

    Syntax: ELEC_ENERGY_TOL [Value] [Unit]
    Description: Convergence criterion for minimisation of electronic energy: Energy change per NGWF optimisation iteration must be less than this amount PER ATOM before the calculation is regarded as converged. Ignored if negative.
    Default Value:

    -0.001 hartree

    Example: elec_energy_tol 0.00001 eV
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    ELEC_FORCE_TOL

    Syntax: ELEC_FORCE_TOL [Value] [Unit]
    Description: Convergence criterion for minimisation of electronic energy: Maximum change in any component of the forces from NGWF optimisation iteration to the next must be less than this amount before the calculation is regarded as converged. Ignored if negative.
    Default Value:

    -0.001 "ha/bohr"

    Example: elec_force_tol 0.01 "eV/ang"
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    ETRANS_BULK

    Syntax: ETRANS_BULK [Logical]
    Description: Compute the bulk transmission coefficients of the individual leads defined in ETRANS_LEADS.
    Default Value:

    False

    Example: etrans_bulk T
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    ETRANS_CALCULATE_LEAD_MU

    Syntax: ETRANS_CALCULATE_LEAD_MU [Logical]
    Description: Calculate the lead chemical potentials via a non-self consistent band structure calculation. The band structure for each lead is written to a .bands file. Defaults to TRUE is ETRANS_EREF_METHOD = LEADS.
    Default Value:

    False, unless ETRANS_EREF_METHOD = LEADS

    Example: etrans_calculate_lead_mu T
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    ETRANS_ECMPLX

    Syntax: ETRANS_ECMPLX [Value] [Unit]
    Description: Small imaginary part added to the energy in order to impose the appropriate boundary condition to the computed retarded Green's function. This parameter should theoretically tends toward zero. If set too small, instabilities may occur and the calculation of the Green's function may fail.
    Default Value:

    1.0E-6 hartree

    Example: etrans_ecmplx 0.00001 hartree
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    ETRANS_EMAX

    Syntax: ETRANS_EMAX [Value] [Unit]
    Description: Highest energy for the calculation of the transmission coefficients (defined with respect to the reference level). Transmission coefficients are calculated in the range ETRANS_MIN <= E - ETRANS_EREF <= ETRANS_MAX.
    Default Value:

    0.2 hartree

    Example: etrans_emax 0.2 hartree
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    ETRANS_EMIN

    Syntax: ETRANS_EMIN [Value] [Unit]
    Description: Lowest energy for the calculation of the transmission coefficients (defined with respect to the reference level). Transmission coefficients are calculated in the range ETRANS_MIN <= E - ETRANS_EREF <= ETRANS_MAX.

    Default Value:

    -0.2 hartree

    Example: etrans_emin -0.2 hartree
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    ETRANS_ENUM

    Syntax: ETRANS_ENUM [Integer]
    Description: Number of energy points equally spaced between ETRANS_EMIN and ETRANS_EMAX for the calculation of the electronic transmission coefficients as a function of the energy.
    Default Value:

    50

    Example: etrans_enum 100
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    ETRANS_EREF

    Syntax: ETRANS_EREF [Value] [Unit]
    Description: If ETRANS_EREF_METHOD = REFERENCE, this defines the reference energy about which transmission is calculated. Transmission coefficients are calculated in the range ETRANS_MIN <= E - ETRANS_EREF <= ETRANS_MAX. If any other ETRANS_EREF_METHOD is chosen, this energy is determined automatically according to that method.
    Default Value:

    0.0 hartree

    Example: etrans_eref 0.0 hartree
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    ETRANS_EREF_METHOD

    Syntax: etrans_eref_method [Text]
    Description: The method to determine the reference energy for the calculation of transmission coefficients. Options are: LEADS (take the average chemical potential of the leads), REFERENCE (explicitly set the reference energy using ETRANS_EREF), DIAG (use the mid-gap level of the entire system). LEADS and REFERENCE are independent of system size. DIAG scales cubically with system size, and will be unsuitable for very large systems. (Calculating the Green's function currently scales cubically also, however a linear-scaling recursive algorithm is in development.)
    Default Value:

    DIAG

    Example: etrans_eref_method REFERENCE
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    ETRANS_LCR

    Syntax: ETRANS_LCR [Logical]
    Description: Compute the 'Left-Centre-Right' transmission coefficients between all leads defined in ETRANS_LEADS. Transmission occurs through the device region defined in ETRANS_BULK.
    Default Value:

    False

    Example: etrans_lcr T
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    ETRANS_LEADS

    Syntax:

    %BLOCK ETRANS_LEADS
    lead_start lead_end principle_layer_start principle_layer_end
    lead_start lead_end principle_layer_start principle_layer_end
    ...
    %ENDBLOCK ETRANS_LEADS

    Description: Defines the atoms that form the leads for the calculation of the transport coefficients. Each line of the block defines a lead, consisting of four numbers. The first two numbers define the first and last atom contained within the lead; the second two numbers define the first and last atom that form the principle layer for that lead. The leads should form a bulk periodic unit cell. The atoms in the principle layer should be a periodic repeat, in the same atomic ordering, as the lead atoms. How strictly this is enforced is controlled by ETRANS_LEAD_DISP_TOL.

    The principle layer should define the the only set of atoms that the lead interacts with; the lead interacts with the central region through the principle layer. A lead should not directly interact with any other lead.

    The atoms are ordered by their order in the input file. This block is mandatory when ETRANS_LCR and/or ETRANS_BULK is set to true.
    Default Value:
    Example:

    In this example, three leads are defined containing 36, 60 and 20 atoms.


    %block etrans_leads
    037 072 073 108
    241 300 301 360
    601 640 561 600
    %endblock etrans_leads

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    ETRANS_LEAD_DISP_TOL

    Syntax: ETRANS_LEAD_DISP_TOL [Value] [Unit]
    Description: The maximum acceptable difference in the translation vectors between the atoms in a lead, and the corresponding atoms in the lead principle layer. If the principle layer geometry is an exact repeat of the lead geometry, the translation vectors will all be identical. This parameter allows for this criterion to be relaxed.
    Default Value:

    1.0 bohr

    Example: etrans_lead_disp_tol 1.0 bohr
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    ETRANS_LEAD_NKPOINTS

    Syntax: ETRANS_LEAD_NKPOINTS [Integer]
    Description: The number of kpoints the lead band structure is calculated for. The kpoints are equally spaced between [0,pi/a].
    Default Value:

    32

    Example: etrans_lead_nkpoints 100
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    ETRANS_SAME_LEADS

    Syntax: ETRANS_SAME_LEADS [Logical]
    Description: Use the same self energy for all leads. If all leads are identical, this may give a very small computational saving. Warning: this may still be a bad approximation for leads with the same geometry.
    Default Value:

    False

    Example: etrans_same_leads T
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    ETRANS_SETUP

    Syntax:

    %BLOCK ETRANS_SETUP
    atom_start atom_stop
    %ENDBLOCK ETRANS_SETUP

    Description: Defines the atoms used for the calculation of the transport coefficients. The block should contain a single line giving the index of the first and last atom contained within the transport calculation. All atoms between these indices (inclusive) are included, with all other atoms considered as buffer and ignored. These indices must contain all the leads, and the central scattering region. The atoms are ordered by their order in the input file. This block is mandatory when ETRANS_LCR is set to true.
    Default Value:
    Example:

    In this example, all atoms between 37 and 640 will be used. All other atoms are considered as buffer atoms. Note: This syntax is not compatible with versions earlier than ONETEP 3.3.4


    %block etrans_setup
    037 640
    %endblock etrans_setup

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    ETRANS_WRITE_HS

    Syntax: ETRANS_WRITE_HS [Logical]
    Description: Write the lead and LCR Hamiltonian and Overlap matrices to disk for further analysis. The binary file format description is given in etrans_mod.F90. Warning: these matrices can be very large.
    Default Value:

    False

    Example: etrans_write_hs T
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    EVEN_PSINC_GRID

    Syntax: EVEN_PSINC_GRID [Logical]
    Description: Force even number of points in the simulation-cell psinc grid.
    Default Value:

    False

    Example: even_psinc_grid T
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    EXACT_LNV

    Syntax: EXACT_LNV [Logical]
    Description: Specifies that the normalization constraint on the density matrix should be imposed exactly, using the purified density kernel (as in the original Li-Nunes-Vanderbilt algorithm [Phys. Rev. B47, 10891 (1993)]) rather than the auxiliary kernel (as in the Millam-Scuseria variant [J. Chem. Phys.106, 5569 (1997)]).
    Default Value:

    True

    Example: exact_lnv F
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    EXTERNAL_BC_FROM_CUBE

    Syntax: EXTERNAL_BC_FROM_CUBE [Logical]
    Description: If this flag is True, external boundary conditions for the electrostatic potential are imposed according to the contents of the cube file rootname_POT_EXT_BC.cube.

    This cube file needs to match the dimensions of the FD multigrid (see the implicit solvation documentation for more details).
    Default Value:

    False

    Example: external_bc_from_cube : T
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    EXTERNAL_PRESSURE

    Syntax: EXTERNAL_PRESSURE [Physical]
    Description: Value of the input pressure Pin in the electronic enthalpy functional H=U+PV where U is the total Kohn-Sham internal energy of the system and V is a volume definition based on an electronic-density isosurface (determined by the SMOOTHING_FACTOR and ISOSURFACE_CUTOFF keywords). The electronic enthalpy can be minimized self-consistently during geometry relaxation or MD runs and allows for constant pressure simulation of finite systems [Cococcioni et al, Phys. Rev. Lett.94, 145501 (2005)]. The implementation is described in more detail in [Corsini et al, J. Chem. Phys. 2013, 139, 084117].
    Default Value:

    0.0 GPa

    Example: external_pressure 1.0 gpa
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    EXTRA_N_SW

    Syntax: EXTRA_N_SW [Integer]
    Description: Generates extra spherical waves for the NGWFs representation. The extra SW will suffer of aliasing as their frequency is higher than the maximum plane waves basis set given by the kinetic cut-off.
    Default Value:

    0

    Example: extra_n_sw 10
    Example: extra_n_sw -5
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    FFTBOX_BATCH_SIZE

    Syntax: FFTBOX_BATCH_SIZE [Int]
    Description: Number of NGWFs in each batch of fftboxes.
    Default Value:

    16

    Example: fftbox_batch_size 8
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    FFTBOX_PREF

    Syntax: FFTBOX_PREF [Text]
    Description: Specifies a size for the FFT-box that is preferable to the smallest possible size that would normally be chosen (e.g. if the FFT library on a particular machine favours certain sizes). The FFT-box is specified by three integers (which must all be odd) that give the number of coarse grid points in thea1,a2anda3directions respectively.
    Default Value:

    0 0 0 ; use smallest possible

    Example: fftbox_pref 65 65 65
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    FINE_GRID_SCALE

    Syntax: FINE_GRID_SCALE [Real]
    Description: Specifies the spacing of the fine grid as a multiple of the spacing of the standard grid (which is determined by psinc_spacing or by cutoff_energy).
    Default Value:

    2.0 ;

    Example: fine_grid_scale 4.0
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    FOE

    Syntax: FOE [Logical]
    Description: Enable calculation of the density kernel with a Fermi Operator Expansion approach in finite-temperature DFT calculations with the Ensemble-DFT method. This method is recommended when the calculation contains more than ~1000 atoms. EDFT should also be enabled.
    Default Value:

    F

    Example: foe T
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    FOE_AVOID_INVERSIONS

    Syntax: FOE_AVOID_INVERSIONS [Logical]
    Description: In the FOE method, several matrix inversions are necessary to calculate the finite temperature density kernel. If this parameter is enabled, the matrix solves are instead approximated by Chebyshev expansions. This may be more accurate with a given sparsity pattern, but is likely to be slightly slower than calculating the inverses iteratively.
    Default Value:

    F

    Example: foe_avoid_inversions T
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    FOE_CHEBY_THRES

    Syntax: FOE_CHEBY_THRES [Real]
    Description: When the FOE method builds up an approximation for the density kernel in powers of the Hamiltonian matrix, the maximum term in the Chebyshev expansion is determined by this parameter.
    Default Value:

    1.0e-9;

    Example: foe_cheby_thres 1.0e-10
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    FOE_CHECK_ENTROPY

    Syntax: FOE_CHECK_ENTROPY [Logical]
    Description: In the FOE method, the entropy matrix is also calculated as an expansion (in powers of the density kernel) to calculate the entropy itself. This expansion is prone to divergence, so to check for this, and to correct it if it happens, the result is checked against a simple quadratic approximation to the entropy matrix which cannot diverge.
    Default Value:

    T

    Example: foe_check_entropy T
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    FOE_MU_TOL

    Syntax: FOE_MU_TOL [Value] [Unit]
    Description: The performance of the FOE method is affected strongly by how accurately the chemical potential is determined. This parameter should be tuned by the user to find an accurate energy, while minimising the number of iterations in FOE.
    Default Value:

    1e-7 hartree

    Example: foe_mu_tol 1.0e-9 hartree
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    FOE_TEST_SPARSITY

    Syntax: FOE_TEST_SPARSITY [Value]
    Description: If using the AQuA-FOE method, the sparsity pattern is mainly determined by the NGWF radii. To determine the accuracy of this approximation, this parameter can be enabled to print out an estimate.
    Default Value:

    False

    Example: foe_test_sparsity F hartree
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    GEOM_BACKUP_ITER

    Syntax: GEOM_BACKUP_ITER [Integer]
    Description: Specifies the backup frequency for geometry optimisation. If the input filename is rootname.dat then the backup filename is rootname.continuation .
    Default Value:

    1 ; every iteration

    Example: geom_backup_iter 5
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    GEOM_CONTINUATION

    Syntax: GEOM_CONTINUATION [Logical]
    Description: Continue a geometry optimization from a previous run using the .continuation backup file.
    Default Value:

    False

    Example: geom_continuation T
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    GEOM_CONVERGENCE_WIN

    Syntax: GEOM_CONVERGENCE_WIN [Integer]
    Description: Specifies the number of consecutive iterations during which the convergence criteria must be met.
    Default Value:

    2

    Example: geom_convergence_win 3
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    GEOM_DISP_TOL

    Syntax: GEOM_DISP_TOL [Value] [Unit]
    Description: Specifies atomic displacement tolerance used as one of the criteria for convergence of geometry optimization. The positions of all atoms must change by less than this tolerance to satisfy this criterion.
    Default Value:

    0.005 bohr

    Example: geom_disp_tol 1.0e-4 nm
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    GEOM_ENERGY_TOL

    Syntax: GEOM_ENERGY_TOL [Value] [Unit]
    Description: Specifies the tolerance for enthalpy per atom over the convergence window as a criterion for geometry optimization convergence.
    Default Value:

    1.0E-6 hartree

    Example: geom_energy_tol 0.2 meV
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    GEOM_FORCE_TOL

    Syntax: GEOM_FORCE_TOL [Value] [Unit]
    Description: Specifies the tolerance for maximum atomic force as a criterion for geometry optimization convergence. Note that units involving a forward slash (/) must be quoted as in the example below.
    Default Value:

    0.002 "ha/bohr"

    Example: geom_force_tol 0.1 "ev/ang"
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    GEOM_FREQUENCY_EST

    Syntax: GEOM_FREQUENCY_EST [Value] [Unit]
    Description: Specifies the estimated average phonon frequency (as an energy) used to initialize the inverse Hessian matrix for geometry optimization.
    Default Value:

    0.0076 hartree

    Example: geom_frequency_est 0.2 eV
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    GEOM_LBFGS

    Syntax: GEOM_LBFGS [Logical]
    Description: If the history length (GEOM_LBFGS_MAX_UPDATES) is set to 0 then LBFGS will perform a geometry optimisation equivalent to the BFGS method. If combined with a limited history length, however, it will store only the latest number of history vectors of length nDOF (number of degrees of freedom) rather than nDOF^2 of them. This potentially allows for larger calculations, where storage of the full Hessian matrix is impossible.
    Default Value:

    False

    Example: geom_lbfgs F
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    GEOM_LBFGS_BLOCK_LENGTH

    Syntax: GEOM_LBFGS_BLOCK_LENGTH [Integer]
    Description: If LBFGS is performed in unbounded mode, then the geometry optimiser should perform identically to BFGS, however, to avoid using as much memory as BFGS, the number of history vectors which are stored is increased in increments of GEOM_LBFGS_BLOCK_LENGTH. So, provided that the number of iterations of the geometry optimiser does not reach ~1/2 * number of degrees of freedom, then it will use less memory than a standard BFGS calculation.
    Default Value:

    30

    Example: geom_lbfgs_block_length 30
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    GEOM_LBFGS_MAX_UPDATES

    Syntax: GEOM_LBFGS_MAX_UPDATES [Integer]
    Description: The LBFGS method can optionally limit the number of history vectors which it uses to build an approximation to he inverse Hessian to the latest N. This can vastly reduce the memory requirements if N is small, but the user should ensure that N is large enough that the approximation is sufficient. If N is set to 0 then LBFGS keeps an unlimited history, which is equivalent to BFGS.
    Default Value:

    30

    Example: geom_lbfgs_max_updates 30
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    GEOM_MAX_ITER

    Syntax: GEOM_MAX_ITER [Integer]
    Description: Specifies the maximum number of iterations for geometry optimisation.
    Default Value:

    50

    Example: geom_max_iter 30
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    GEOM_METHOD

    Syntax: GEOM_METHOD [Text]
    Description: Specifies the method for geometry optimisation, currently either CARTESIAN for the BFGS algorithm based on Cartesian atomic coordinates [e.g. Pfrommeret al.,J. Comp. Phys.131, 233 (1997)] or DELOCALIZED for delocalized internal coordinates [Andzelm et al., Chem. Phys. Lett., 335, 321, (2001)].
    Default Value:

    CARTESIAN

    Example: geom_method DELOCALIZED
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    GEOM_MODULUS_EST

    Syntax: GEOM_MODULUS_EST [Value] [Unit]
    Description: Specifies the estimated bulk modulus used to initialize the inverse Hessian matrix for geometry optimization.
    Default Value:

    0.017 "ha/bohr**3"

    Example: geom_modulus_est 100 GPa
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    GEOM_PRECOND_EXP_A

    Syntax: GEOM_PRECOND_EXP_A [Real]
    Description: This is a parameter in the EXP geometry optimisation pre-conditioning scheme explained in:
    Packwood, David, et al. "A universal preconditioner for simulating condensed phase materials." The Journal of Chemical Physics 144.16 (2016): 164109.
    The convergence of the geometry optimisation is "relatively insensitive" to this parameter, but it can be tweaked to obtain slightly faster convergence if desired.
    Default Value:

    3.0 ;

    Example: geom_precond_EXP_A 3.0
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    GEOM_PRECOND_EXP_C_STAB

    Syntax: GEOM_PRECOND_EXP_C_STAB [Value] [Unit]
    Description: Specifies a diagonal contribution to add onto the ionic part of the Hessian pre-conditioning matrix in LBFGS / EXP pre-conditioning. This can improve stability if increased in magnitude, but should be left alone if the geometry optimisation is converging.
    Default Value:

    0.1 "ha/bohr**2"

    Example: geom_precond_exp_c_stab 0.15 ha/bohr**2
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    GEOM_PRECOND_EXP_MU

    Syntax: GEOM_PRECOND_EXP_MU [Value] [Unit]
    Description: This pre-conditioner scaling parameter is calculated automatically if set to the default value of 0. The value found automatically is not guaranteed to give the best convergence, but has performed well empirically. The user may experiment with values to give faster convergence.
    Default Value:

    0.0 "ha/bohr**2"

    Example: geom_precond_exp_mu 0.1 ha/bohr**2
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    GEOM_PRECOND_EXP_R_CUT

    Syntax: GEOM_PRECOND_EXP_R_CUT [Value] [Unit]
    Description: Specifies an upper limit in atomic separation to consider when calculating terms in the preconditioning matrix, with LBFGS / EXP pre-conditioning. A lower value is faster, but a larger value will give a potentially better pre-conditioning matrix. This is calculated from the nearest neighbour distance GEOM_PRECOND_EXP_R_NN by default.
    Default Value:

    0.0 "bohr"

    Example: geom_precond_exp_r_cut 4.0 bohr
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    GEOM_PRECOND_EXP_R_NN

    Syntax: GEOM_PRECOND_EXP_R_NN [Value] [Unit]
    Description: If set to 0.0, as it is by default, the nearest neighbour distance is calculated automatically. This is used to calculate the distance cutoff in the EXP LBFGS pre-conditioner.
    Default Value:

    0.0 "bohr"

    Example: geom_precond_exp_r_NN 4.0 bohr
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    GEOM_PRECOND_FF_C_STAB

    Syntax: GEOM_PRECOND_FF_C_STAB [Value] [Unit]
    Description: Specifies a diagonal contribution to add onto the ionic part of the Hessian pre-conditioning matrix in LBFGS / FF pre-conditioning. This can improve stability if increased in magnitude, but should be left alone if the geometry optimisation is converging.
    Default Value:

    0.1 "ha/bohr**2"

    Example: geom_precond_ff_c_stab 0.15 ha/bohr**2
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    GEOM_PRECOND_FF_R_CUT

    Syntax: GEOM_PRECOND_FF_R_CUT [Value] [Unit]
    Description: Specifies an upper limit in atomic separation to consider when calculating terms in the preconditioning matrix, with LBFGS / FF pre-conditioning. A lower value is faster, but a larger value will give a potentially better pre-conditioning matrix.
    Default Value:

    3.8 "bohr"

    Example: geom_precond_ff_r_cut 4.0 bohr
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    GEOM_PRECOND_TYPE

    Syntax: GEOM_PRECOND_TYPE [Text]
    Description: If this is set to NONE, then LBFGS will use the Pfrommer pre-conditioner as normal. If it is set to ID, then a scaled identity matrix will be used as the pre-conditioning matrix. If set to EXP, then an exponential pre-conditioner will be used which can reduce the number of geometry iterations in inorganic calculations to less than half. For organic calculations, the FF, forcefield pre-conditioning method is recommended which can reduce the number of geometry iterations to about a third of the number with geom_precond_type : F. The FF method does not support atomic species beneath row 3 in the periodic table. More information on these methods may be found in :
    Packwood, David, et al. "A universal preconditioner for simulating condensed phase materials." The Journal of Chemical Physics 144.16 (2016): 164109.
    Default Value:

    NONE

    Example: geom_precond_type EXP
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    GEOM_PRINT_INV_HESSIAN

    Syntax: GEOM_PRINT_INV_HESSIAN [Logical]
    Description: Include information about the inverse Hessian matrix in the ouput of a geometry optimization.
    Default Value:

    False

    Example: geom_print_inv_hessian T
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    GEOM_RESET_DK_NGWFS_ITER

    Syntax: GEOM_RESET_DK_NGWFS_ITER [Integer]
    Description: Number of geom iterations between resets of kernel and NGWFs
    Default Value:

    6

    Example: geom_reset_dk_ngwfs_iter 20
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    GEOM_REUSE_DK_NGWFS

    Syntax: GEOM_REUSE_DK_NGWFS [Logical]
    Description: Re-use density kernel and NGWFs during geometry optimisation steps
    Default Value:

    True

    Example: geom_reuse_dk_ngwfs F
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    GRD_FORMAT

    Syntax: GRD_FORMAT [Logical]
    Description: Output volumetric data (e.g. charge density, potential, NGWFs, canonical orbitals) in .grd format used by Accelrys Materials Studio .
    Default Value:

    False

    Example: grd_format F
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    H2DENSKERN_SPARSITY

    Syntax: H2DENSKERN_SPARSITY [Logical]
    Description: Enable the AQuA-FOE method when FOE and EDFT are both enabled. This allows the sparsity of the density kernel to be adjusted by the NGWF radii. This approach should be faster for calculations with > 1000 atoms, and explicitly allows sparsity in the density kernel.
    Default Value:

    F

    Example: h2denskern_sparsity T
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    HOMO_DENS_PLOT

    Syntax: HOMO_DENS_PLOT [Integer]
    Description: Specifies the number of canonical orbitals below the HOMO to plot, if DO_PROPERTIES is set to true. Thus a value of zero plots only the HOMO, a negative value disables plotting and a positive value of N plots the N+1 highest occupied canonical orbitals.
    Default Value:

    -1

    Example: homo_dens_plot 0
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    HOMO_PLOT

    Syntax: HOMO_PLOT [Integer]
    Description: Specifies the number of canonical orbitals below the HOMO to plot, if DO_PROPERTIES is set to true. Thus a value of zero plots only the HOMO, a negative value disables plotting and a positive value of N plots the N+1 highest occupied canonical orbitals.
    Default Value:

    5 ; plot the HOMO and the five canonical orbitals below

    Example: homo_plot 0
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    HUBBARD

    Syntax: HUBBARD [Block]
    Syntax:

    %BLOCK HUBBARD
    S1 L1 U1 J1 Z1 a1 s1
    S2 L2 U2 J2 Z2 a2 s2
    . . . . .
    . . . . .
    SN LN UN JN ZN aN sN
    %ENDBLOCK HUBBARD

    Description: Applies the DFT+U, also known as LDA+U, correction for strongly correlated materials. For species S and correlated subspace of angular momentum channel L (with principal quantum number n=L+1) we apply a DFT+U correction with Hubbard parameter U (eV) and exchange parameter J (eV). Standard DFT+U functionality can be obtained by setting J=0.

    The effective nuclear charge Z determines how the projectors defining the correlated subspace are generated. If any negative value is given, e.g., Z=-10, the NGWF initial guess orbitals (numerical atomic orbitals) are used. Alternatively, a positive value of Z causes the code to generate hydrogenic orbitals spanning this space with effective nuclear charge Z.

    The a and s parameters (eV) are a rigid potential shift and a spin-splitting, respectively, applied to the subspaces.

    For more information, please read the file in the documentation section.
    Default Value:
    Example:

    %block hubbard
    O 1 0.0 0.0 -4.5 0.0 0.0
    Fe 2 3.0 0.0 -9.5 0.0 0.0
    %endblock hubbard

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    HUBBARDSCF_ON_THE_FLY

    Syntax: HUBBARDSCF_ON_THE_FLY [Logical]
    Description: Activate a non-variational on-the-fly form of projector self-consistency in DFT+U or cDFT, in which the projectors are updated whenever the NGWFs are. task : HUBBARDSCF is then not needed.
    Default Value:

    False

    Example: hubbardscf_on_the_fly T
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    HUBBARD_CONV_WIN

    Syntax: HUBBARD_CONV_WIN [Integer]
    Description: The minimum number of Hubbard projector update steps satisfying the incremental energy tolerance HUBBARD_ENERGY_TOL required for convergence in task : HUBBARDSCF.
    Default Value:

    2

    Example: hubbard_conv_win 4
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    HUBBARD_ENERGY_TOL

    Syntax: HUBBARD_ENERGY_TOL [Value] [Unit]
    Description: The maximum incremental energy change between Hubbard projector update steps allowed for converge in task : HUBBARDSCF.
    Default Value:

    1.0E-8 Ha

    Example: hubbard_energy_tol 1.0E-4 eV
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    HUBBARD_FUNCTIONAL

    Syntax: HUBBARD_FUNCTIONAL [Real]
    Description: The form of DFT+U energy term used. Contact developers if you need to try something beyond the default.
    Default Value:

    1

    Example: hubbard_functional 1
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    HUBBARD_MAX_ITER

    Syntax: HUBBARD_MAX_ITER [Integer]
    Description: The maximum allowed number of Hubbard projector update steps taken in a projector self-consistent DFT+U or cDFT calculation in task : HUBBARDSCF.
    Default Value:

    10

    Example: hubbard_max_iter 6
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    HUBBARD_NGWF_SPIN_THRESHOLD

    Syntax: HUBBARD_NGWF_SPIN_THRESHOLD [Value] [Unit]
    Description: The incremental change in energy, in total-energy minimisation, at which any spin-splitting (Zeeman) type term in DFT+U is switched off, and the minimisation history reset. Useful for breaking open-shell, antiferromagnetic, or charge-density wave symmetries.
    Default Value:

    2.0E-5 Ha

    Example: hubbard_ngwf_spin_threshold 1.0E-3 eV
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    HUBBARD_PROJ_MIXING

    Syntax: HUBBARD_PROJ_MIXING [Real]
    Description: The fraction of previous Hubbard projector to mix with new for projector self-consistent DFT+U or cDFT in task : HUBBARDSCF. Not found to be necessary.
    Default Value:

    0.0

    Example: hubbard_proj_mixing 0.2
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    HUBBARD_READ_PROJECTORS

    Syntax: HUBBARD_READ_PROJECTORS [Logical]
    Description: Read Hubbard projectors from .tightbox_hub_projs file in restart calculations involving DFT+U.
    Default Value:

    False

    Example: hubbard_read_projectors T
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    HUBBARD_TENSOR_CORR

    Syntax: HUBBARD_TENSOR_CORR [Integer]
    Description: The form of correction used to correct for any nonorthogonality between Hubbard projectors. Contact developers if you need to try something other than the default "tensorial" correction.
    Default Value:

    1

    Example: hubbard_tensor_corr 1
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    IMAGE_SIZES

    Syntax: IMAGE_SIZES [Text]
    Description: If specified in the input file, a string of the format ‘i|j|k|l|m|...’ can be used to individually size the images in an image-parallel run. The number of sections specified should be equal the number of images in the run and the sum of the image sizes should be equal the number of MPI processes specified at runtime.
    Default Value:

    DEFAULT

    Example: image_sizes 3|3|5|4
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    INITIAL_DENS_REALSPACE

    Syntax: INITIAL_DENS_REALSPACE [Logical]
    Description: Specifies whether to construct the initial density passed to Palser-Manolopoulos (or diagonalisation) in real-space, from the sum of the atom-solver densities (if true), or the default of a superposition of gaussians (if false).
    Default Value:

    True

    Example: initial_dens_realspace T
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    ISOSURFACE_CUTOFF

    Syntax: ISOSURFACE_CUTOFF [Value]
    Description: Determines the cutoff density alpha of the electronic density isosurface defining the volume Ve used in the electronic enthalpy method. Care must be taken to calibrate its value, along with SMOOTHING_FACTOR, for the system of interest as described in [Corsini et al, J. Chem. Phys. 2013, 139, 084117]
    Default Value:

    0.0005

    Example: isosurface_cutoff 0.0003
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    IS_APOLAR_SCALING_FACTOR

    Syntax: IS_APOLAR_SCALING_FACTOR [Value]
    Description: Controls the scaling of the apolar term with the aim of taking solute-solvent dispersion-repulsion into account. This is only relevant in implicit solvent calculations.
    Default Value:

    0.281075

    Example: IS_APOLAR_SCALING_FACTOR 1.0
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    IS_AUTO_SOLVATION

    Syntax: IS_AUTO_SOLVATION [Logical]
    Description: Specifies that a calculation in vacuum should be automatically performed before any calculation that employs implicit solvent.
    Default Value:

    False

    Example: is_auto_solvation T
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    IS_BC_COARSENESS

    Syntax: IS_BC_COARSENESS [Integer]
    Description: Specifies the edge length of the cubic block, in units of fine grid delta, over which charge will be coarse-grained in the calculation of open boundary conditions. This is only relevant in implicit solvent calculations and in calculations with open boundary conditions (such as calculations with smeared ions).
    Default Value:

    5

    Example: is_bc_coarseness 7 ; Use blocks 7x7x7
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    IS_BC_SURFACE_COARSENESS

    Syntax: IS_BC_SURFACE_COARSENESS [Integer]
    Description: Specifies the edge length of the square block, in units of fine grid delta, over which the potential will be bilinearly interpolated in the calculation of open boundary conditions. This is only relevant in implicit solvent calculations and in calculations with open boundary conditions (such as calculations with smeared ions). Values larger than 1 will speed up the calculation but can impact accuracy for charged systems -- use with care.
    Default Value:

    1

    Example: is_bc_surface_coarseness 3 ; Use surface blocks of 3x3
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    IS_BC_THRESHOLD

    Syntax: IS_BC_THRESHOLD [Real]
    Description: Specifies the charge density threshold used for coarse-graining in the calculation of open boundary conditions. Fine grid points with charge magnitudes below this threshold will be ignored during the coarse-graining procedure. This serves to eliminate the unnecessary integration of noise and ringing. Decreasing this threshold (to, say, 1E-10) might be necessary in rare situations, such as in runs using simulation cells with inadequate padding and fine_grid_scale > 2.0, which may lead to more severe ringing. Increasing this threshold mainly serves to increase performance, however, accuracy will be impacted if this threshold is set too high (higher than, say, 5E-8).

    This is only relevant in implicit solvent calculations and in calculations with open boundary conditions (such as calculations with smeared ions).

    Default Value:

    1.0E-9

    Example: is_bc_threshold 1E-10 ; Be extra accurate
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    IS_BULK_PERMITTIVITY

    Syntax: IS_BULK_PERMITTIVITY [Value]
    Description: Sets the relative dielectric permittivity of the solvent.
    Default Value:

    1.0 (80.0 if IS_IMPLICIT_SOLVENT T) -- for v3.0.0 to 4.4.5 and v4.5.0.
    1.0 (78.54 if IS_IMPLICIT_SOLVENT T) -- for v4.4.6 and v4.5.1 and newer.

    Example: IS_BULK_PERMITTIVITY 14.2 ; ethanediamine as solvent
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    IS_CHECK_SOLV_ENERGY_GRAD

    Syntax: IS_CHECK_SOLV_ENERGY_GRAD [Logical]
    Description: Checks the gradient of solvation energy with finite differences. This is only relevant in implicit solvent calculations.
    Default Value:

    False

    Example: IS_CHECK_SOLV_ENERGY_GRAD T
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    IS_CORE_WIDTH

    Syntax: IS_CORE_WIDTH [Physical]
    Description: Only used in implicit solvent calculations. In the IS model used in ONETEP the dielectric permittivity is a function of electronic density. For certain atoms (e.g. Pt) the use of pseudopotentials may cause the electronic density in the immediate vicinity of an atom to be so low as to produce permittivities that non-negligibly differ from 1. By using this directive you can specify a radius around each core where the permittivity is set to unity regardless of the usual definition of eps=eps(rho). We've not yet seen a case where the default would be unsuitable.
    Default Value:

    1.2 bohr

    Example: is_core_width 1.4 bohr
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    IS_DENSITY_THRESHOLD

    Syntax: IS_DENSITY_THRESHOLD [Value]
    Description: Sets the value of the rho_0 parameter (in atomic units) in the definition of the dielectric cavity as described in DA Scherlis, J-L Fattebert, F Gygi, M Cococcioni, and N Marzari, Journal of Chemical Physics 124, 074103 (2006). This is only relevant in implicit solvent calculations.
    Default Value:

    0.00078 (v3.0.0 to v4.4.5, v4.5.0)
    0.00035 (v4.4.6, v4.5.1 and newer)

    Example: IS_DENSITY_THRESHOLD 0.00035
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    IS_DIELECTRIC_EXCLUSIONS

    Syntax:

    %BLOCK IS_DIELECTRIC_EXCLUSIONS
    sphere x y z r OR box xmin xmax ymin ymax zmin zmax
    ... ... ...
    %ENDBLOCK IS_DIELECTRIC_EXCLUSIONS

    Description: In typical applications this block can be absent. If not absent, it is used to determine which additional parts of the system are inaccessible to the implicit solvent.
    Default Value:

    (absent)

    Example:

    %block is_dielectric_exclusions
    sphere 20.0 15.0 22.0 4.0 ; x, y, z and radius, all in bohr
    box 13.0 15.0 10.0 14.5 22.5 29.0 ; xmin xmax ymin ymax zmin zmax, all in bohr
    xcyl 17.0 45.0 7.0 ; y, z and radius, all in bohr
    %endblock is_dielectric_exclusions



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    4.5.11.14

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    IS_DIELECTRIC_EXCLUSIONS_SMEAR

    Syntax: is_dielectric_exclusions_smear [Value] [Unit]
    Description: Length scale that defines the extent of the smearing of dielectric exclusion region boundaries. For more details, see the implicit solvation documentation.
    Default Value:

    0 Bohr

    Example: is_dielectric_exclusions_smear 0.5 Bohr
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    IS_DIELECTRIC_FUNCTION

    Syntax: IS_DIELECTRIC_FUNCTION [FGF | GAUSSIAN]
    Description: Chooses the function used to generate the dielectric cavity from the electronic density. FGF uses the one described in DA Scherlis, J-L Fattebert, F Gygi, M Cococcioni, and N Marzari, Journal of Chemical Physics 124, 074103 (2006). GAUSSIAN uses the core density to generate the cavity, this is not currently supported. This is only relevant in implicit solvent calculations.
    Default Value:

    FGF

    Example: IS_DIELECTRIC_FUNCTION FGF
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    IS_DIELECTRIC_MODEL

    Syntax: IS_DIELECTRIC_MODEL [FIX_INITIAL | SELF_CONSISTENT | GAUSSIAN_IONS]
    Description: Chooses how the dielectric cavity responds to changes in the electronic density. With FIX_INITIAL the cavity remains fixed (and the calculation is still self-consistent). With SELF_CONSISTENT, the cavity self-consistently reacts to changes in the density. With GAUSSIAN_IONS the core density is used to generate the cavity, so it remains fixed as well. GAUSSIAN_IONS is not currently supported. FIX_INITIAL is strongly recommended. SELF_CONSISTENT offers slightly improved accuracy, but requires very fine grids to converge (such as FINE_GRID_SCALE 4.0), which translates into extremely high memory requirements -- thus it is not recommended, unless for very small molecules. This keyword is only relevant in implicit solvent calculations.
    Default Value:

    FIX_INITIAL

    Example: IS_DIELECTRIC_MODEL SELF_CONSISTENT
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    IS_DISCRETIZATION_ORDER

    Syntax: IS_DISCRETIZATION_ORDER [Integer]
    Description: Sets the discretization order used for finite-differences. The available orders are: 2, 4, 6, 8, 10 and 12. Recommended is 8 or 10. Currently this keyword is only relevant in multigrid calculations (which are those using implicit solvent or open boundary conditions), where it controls the discretization order used for defect-correcting the multigrid solution and for calculating gradients and laplacians.
    Default Value:

    8

    Example: IS_DISCRETIZATION_ORDER 10
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    IS_HC_STERIC_CUTOFF

    Syntax: IS_HC_STERIC_CUTOFF [Physical]
    Description: Specifies the cutoff radius for the hard-core steric potential in implicit solvation with Boltzmann ions. Only relevant for implicit solvation calculations with non-zero salt concentrations. The Boltzmann ions are never allowed within IS_HC_STERIC_CUTOFF from any phyiscal ionic core, or in other words, the solvent ionic accessibility is zero there, and 1 elsewhere. The value will dramatically impact obtained results. Compare: IS_SC_STERIC_CUTOFF.
    Default Value:

    0.0 bohr, corresponding to no hard-core steric potential.

    Example: is_hc_steric_cutoff 3.5 bohr
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    IS_IMPLICIT_SOLVENT

    Syntax: IS_IMPLICIT_SOLVENT [Logical]
    Description: Turns the implicit solvent on or off. As the implicit solvent requires the smeared ion representation, it also sets IS_SMEARED_ION_REP to T. When on, open boundary conditions are used for the calculation of ion-ion, Hartree and local pseudopotential terms.
    Default Value:

    False

    Example: IS_IMPLICIT_SOLVENT T
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    IS_INCLUDE_APOLAR

    Syntax: IS_INCLUDE_APOLAR [Logical]
    Description: When T, includes the apolar term in an implicit solvent calculation. Can only be used with IS_IMPLICIT_SOLVENT T.
    Default Value:

    True if is_implicit_solvent is True, otherwise False.

    Example: IS_INCLUDE_APOLAR F
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    IS_INCLUDE_CAVITATION

    Syntax: IS_INCLUDE_CAVITATION [Logical]
    Description: When T, includes the cavitation term in an implicit solvent calculation. Can only be used with IS_IMPLICIT_SOLVENT T.
    Default Value:

    True if is_implicit_solvent is True, otherwise False.

    Example: IS_INCLUDE_CAVITATION F
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    IS_MULTIGRID_DEFECT_ERROR_TOL

    Syntax: IS_MULTIGRID_DEFECT_ERROR_TOL [Value]
    Description: Sets the error tolerance for the defect-correction algorithm in a multigrid calculation. This controls the maximum error when solving the defect equation in every defect-correction iteration and is *not* directly related to the magnitude of the error in the final solution. This keyword is only relevant in multigrid calculations (which are those using implicit solvent or open boundary conditions).
    Default Value:

    0.01

    Example: IS_MULTIGRID_DEFECT_ERROR_TOL 1E-4 ; Try a stricter tolerance in case defect-correction diverges
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    IS_MULTIGRID_ERROR_DAMPING

    Syntax: is_multigrid_error_damping [Boolean]
    Description: Turns on error damping in the multigrid defect-correction procedure. This is useful for solving the full (non-linearised) Poisson-Boltzmann equation, but will likely not do much for the linearised PBE or for the Poisson equation.
    Default Value:

    False if IS_PBE is NONE or LINEARISED.
    True if IS_PBE is FULL.

    Example: is_multigrid_error_damping T
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    IS_MULTIGRID_ERROR_TOL

    Syntax: IS_MULTIGRID_ERROR_TOL [Value]
    Description: Sets the error tolerance for the solution obtained through multigrid. If IS_DISCRETIZATION_ORDER is larger than 2, this is the final error obtained after defect correction, otherwise this is the error of the uncorrected multigrid solution. This keyword is only relevant in multigrid calculations (which are those using implicit solvent or open boundary conditions).
    Default Value:

    1.0E-5

    Example: IS_MULTIGRID_ERROR_TOL 1E-4 ; Try a relaxed tolerance to speed calculation up
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    IS_MULTIGRID_MAX_ITERS

    Syntax: IS_MULTIGRID_MAX_ITERS [Integer]
    Description: Sets the maximum number of iterations for the multigrid calculation. This controls both the maximum number of defect-correction steps and the maximum number of iterations of the multigrid process in each defect-correction step (and in the first solution with 2nd order, prior to defect correction). This value is best left at its default. This keyword is only relevant in multigrid calculations (which are those using implicit solvent or open boundary conditions).
    Default Value:

    100

    Example: IS_MULTIGRID_MAX_ITERS 200 ; purposefully waste time
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    IS_MULTIGRID_NLEVELS

    Syntax: IS_MULTIGRID_NLEVELS [Integer]
    Description: Sets the number of multigrid levels for a multigrid calculation. This keyword is only relevant in multigrid calculations (which are those using implicit solvent or open boundary conditions).
    Default Value:

    4

    Example: IS_MULTIGRID_NLEVELS 3
    New in:

    3.0.0. Removed in v4.5.13.5

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    IS_MULTIGRID_VERBOSE

    Syntax: IS_MULTIGRID_VERBOSE [Logical]
    Description: Output cross-setions of quantities that are of interest during multigrid calculations to text files. For instance it might be desirable to examine the permittivity to verify whether a pocket in a molecule is solvent-acessible or not. The cross sections are always performed along the X direction, for a given value of Y and Z.
    Default Value:

    False

    Example: is_multigrid_verbose T
    New in:

    4.4.0

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    IS_MULTIGRID_VERBOSE_Y

    Syntax: IS_MULTIGRID_VERBOSE_Y [physical]
    Description: Specifies the offset along the Y axis for cross-sections performed with IS_MULTIGRID_VERBOSE. Make sure you provide units. Compare IS_MULTIGRID_VERBOSE_Z
    Default Value:

    0.0

    Example: IS_MULTIGRID_VERBOSE_Y 14.5 bohr
    New in:

    4.4.0

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    IS_MULTIGRID_VERBOSE_Z

    Syntax: IS_MULTIGRID_VERBOSE_Y [physical]
    Description: Specifies the offset along the Z axis for cross-sections performed with IS_MULTIGRID_VERBOSE. Make sure you provide units. Compare IS_MULTIGRID_VERBOSE_Y
    Default Value:

    0.0

    Example: IS_MULTIGRID_VERBOSE_Y 14.5 bohr
    New in:

    4.4.0

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    IS_PBE

    Syntax: IS_PBE [NONE|LINEARISED|FULL]
    Description: Chooses the equation to be solved in implicit solvation. NONE chooses the nonomogeneous Poisson equation (NPE), LINEARISED chooses the linearised Poisson-Boltzmann equation, FULL chooses the full (non-linearised) Poisson-Boltzmann equation.
    Default Value:

    NONE

    Example: is_pbe FULL
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    IS_PBE_BC_DEBYE_SCREENING

    Syntax: IS_PBE_BC_DEBYE_SCREENING [Boolean]
    Description: Specifies whether boundary conditions in implicit solvation should use Debye screening (lambda*exp) factor. This is only relevant for implicit solvation calculations using the Poisson-Boltzmann formulation. This screening is exact in the linearised formulation, and an approximation in the full formulation.
    Default Value:

    False if IS_PBE is NONE, true otherwise.

    Example: is_pbe_bc_debye_screening F
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    IS_PBE_EXP_CAP

    Syntax: IS_PBE_EXP_CAP [Double]
    Description: Sets a numerical cap at the arguments in the exp() in Poisson-Boltzmann terms in implicit solvation. If this keyword is specified, and uses a value different from 0.0, every argument of an exp() function in Poisson-Boltzmann implicit solvation will be checked against the cap and replaced with the value of the cap if it exceeds the cap. This is a crude way of preventing runaway nonlinearities.

    Note that DL_MG internally caps the cap (!) at max_expcap=50.0, while on the ONETEP side any positive value can be used for the cap. Thus, using values larger that 50.0 will lead to an inconsistency. Anyway, exp(50.0) > 5E21, so tread carefully.
    Default Value:

    0.0, which causes the code to use max_expcap as defined in DL_MG. Currently this is set at 50.0.

    Example: is_pbe_exp_cap 20.0
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    IS_PBE_TEMPERATURE

    Syntax: is_pbe_temperature [Double]
    Description: Sets the temperature for the Boltzmann term in implicit solvation. Has no effect if IS_PBE is set to NONE or if implicit solvation is not in use.
    Default Value:

    300K

    Example: is_pbe_temperature 300.0
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    IS_PBE_USE_FAS

    Syntax: is_pbe_use_fas [Boolean]
    Description: Specifies whether the full aproximation scheme (FAS) should be used for the solution of the Poisson-Boltzmann equation in implicit solvation.
    Default Value:

    False

    Example: is_pbe_use_fas T
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    IS_SC_STERIC_CUTOFF

    Syntax: IS_SC_STERIC_CUTOFF [Physical]
    Description: Specifies the cutoff radius for the soft-core steric potential in implicit solvation with Boltzmann ions. Only relevant for implicit solvation calculations with non-zero salt concentrations. This works vastly differently than the hard-core steric potential (compare IS_HC_STERIC_CUTOFF) -- here this parameter controls mostly computational efficiency, as the soft-core steric potential is only generated within IS_SC_STERIC_CUTOFF from each physical ion core, and assumed to be zero elsewhere. This ensures linear scaling behaviour. The actual values of the steric potentials are controlled via IS_SC_STERIC_MAGNITUDE and IS_SC_STERIC_SMOOTHING_ALPHA. The potential is shifted down by the value at IS_STERIC_CUTOFF to avoid discontinuities.
    Default Value:

    10.0 bohr

    Example: is_sc_steric_cutoff 12.0 bohr
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    IS_SC_STERIC_MAGNITUDE

    Syntax: is_sc_steric_magnitude [Physical]
    Description: Prefactor A in soft-core steric potential in implicit solvation with Boltzmann ions. The soft-core potential is the repulsive part of the LJ potential, i.e. A/r^12 centred around each ion, smoothed by multiplying by erf(IS_SC_STERIC_SMOOTHING_ALPHA*r)^12, then truncated at a truncation radius of IS_SC_STERIC_CUTOFF, and shifted by a tiny amount to be zero at the truncation radius, to avoid a discontinuity.
    Default Value:

    0.0 Ha*bohr^12

    Example: is_sc_steric_magnitude 2000 Ha*bohr^12
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    4.4

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    IS_SC_STERIC_SMOOTHING_ALPHA

    Syntax: IS_SC_STERIC_SMOOTHING_ALPHA [Physical]
    Description: Smoothing factor alpha in soft-core steric potential in implicit solvation with Boltzmann ions. The soft-core potential is the repulsive part of the LJ potential, i.e. IS_STERIC_MAGNITUDE/r^12 centred around each ion, smoothed by multiplying by erf(alpha*r)^12, then truncated at a truncation radius of IS_STERIC_CUTOFF, and shifted by a tiny amount to be zero at the truncation radius, to avoid a discontinuity.
    Default Value:

    1.5 1/bohr

    Example: is_sc_steric_smoothing_alpha 1.2 bohr^-1
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    4.4

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    IS_SEPARATE_RESTART_FILES

    Syntax: IS_SEPARATE_RESTART_FILES [Logical]
    Description: Causes the solute cavity used in implicit solvation calculations to be constructed from a separate set of restart files (.vacuum_dkn, .vacuum_tightbox_ngwfs) from those that are used to restart the calculation itself (.dkn, .tightbox_ngwfs).
    Default Value:

    False

    Example: IS_SEPARATE_RESTART FILES T
    New in:

    3.5.3.2

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    IS_SMEARED_ION_REP

    Syntax: IS_SMEARED_ION_REP [Logical]
    Description: Turns the smeared ion representation on or off. All smeared ion calculations are performed in open boundary conditions. Turning on the smeared ion representation is a necessary condition for performing implicit solvent calculations. Calculations in vacuum that will serve as reference calculations for calculations in solvent should also used smeared ions. Smeared ions are not compatible with cutoff Coulomb (COULOMB_CUTOFF_TYPE) or Martyna-Tuckerman (PBC_CORRECTION_CUTOFF), which are other ways of realizing open boundary conditions.
    Default Value:

    False (True if IS_IMPLICIT_SOLVENT T)

    Example: IS_SMEARED_ION_REP T
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    3.0.0

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    IS_SMEARED_ION_WIDTH

    Syntax: IS_SMEARED_ION_WIDTH [Value] [Unit]
    Description: Sets the smearing width for smeared ions. This is only relevant when IS_SMEARED_ION_REP is @T@. Values larger than default, especially larger than 1.0 bohr, are likely to lead to non-physical results in implicit solvent calculations. Values smaller than default, especially smaller than 0.6 bohr will negatively impact the convergence of the multigrid.
    Default Value:

    0.8 bohr

    Example: IS_SMEARED_ION_WIDTH 0.6 bohr
    New in:

    3.0.0

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    IS_SOLVATION_BETA

    Syntax: IS_SOLVATION_BETA [Value]
    Description: Sets the value of the beta parameter (unitless) in the definition of the dielectric cavity as described in DA Scherlis, J-L Fattebert, F Gygi, M Cococcioni, and N Marzari, Journal of Chemical Physics 124, 074103 (2006). This is only relevant in implicit solvent calculations.
    Default Value:

    1.3

    Example: IS_SOLVATION_BETA 1.6
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    IS_SOLVATION_METHOD

    Syntax: IS_SOLVATION_METHOD [DIRECT | CORRECTIVE]
    Description: Chooses either the direct approach or a corrective approach to solving the Poisson equation in solvent. This keyword is reserved for future development, CORRECTIVE is not currently implemented. This is only relevant in implicit solvent calculations.
    Default Value:

    DIRECT

    Example: IS_SOLVATION_METHOD DIRECT
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    IS_SOLVATION_OUTPUT_DETAIL

    Syntax: IS_SOLVATION_OUTPUT_DETAIL [Text]
    Description: With the sensible default of NONE no additional information is produced. With any other value, regardless of what it is, relevant solvation data, such as densities, potentials, dielectric permittivities, gradient terms are produced in 3D grid formats (cube, dx, grd -- depending on CUBE_FORMAT, DX_FORMAT and GRD_FORMAT) in every step. These consume a lot of disk space and should only be used for debugging.
    Default Value:

    NONE

    Example: IS_SOLVATION_OUTPUT_DETAIL SOME
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    IS_SOLVENT_SURFACE_TENSION

    Syntax: IS_SOLVENT_SURFACE_TENSION [Value] [Unit]
    Description: Sets the surface tension of the solvent. This is only relevant in implicit solvent calculations.
    Default Value:

    4.7624E-5 "Ha/bohr**2" (corresponding to H2O)

    Example: IS_SOLVENT_SURFACE_TENSION 1.33859E-5 ha/bohr**2 ; corresponds to H2O with approximate inclusion of dispersion-repulsion
    New in:

    3.0.0
    Removed in 4.4.6 (main branch) and in 4.5.1 (devel branch).

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    IS_SOLVENT_SURF_TENSION

    Syntax: IS_SOLVENT_SURF_TENSION [Value] [Unit]
    Description: Sets the surface tension of the solvent. This is only relevant in implicit solvent calculations.
    Default Value:

    4.7624E-5 "Ha/bohr**2" (corresponding to H2O, corresponds to 0.07415 N/m).

    Example: IS_SOLVENT_SURF_TENSION 4.7624E-5 ha/bohr**2 ; suitable for H2O, corresponds to 0.07415 N/m
    New in:

    v4.4.6 (main branch)
    v4.5.1 (devel branch)

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    IS_STERIC_WRITE

    Syntax: is_steric_write [Boolean]
    Description: Specifies whether the steric potential (used in implicit solvation with Boltzmann ions) is to be written to a (dx/cube/grd) file.
    Default Value:

    False

    Example: is_steric_write T
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    IS_SURFACE_THICKNESS

    Syntax: IS_SURFACE_THICKNESS [Value]
    Description: Sets the electronic iso-surface thickness (in atomic units of charge density) used to calculate the surface area of the dielectric cavity. This is only relevant in implicit solvent calculations.
    Default Value:

    0.0002

    Example: IS_SURFACE_THICKNESS 0.0003
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    KERNEL_CHRISTOFFEL_UPDATE

    Syntax: KERNEL_CHRISTOFFEL_UPDATE [Logical]
    Description: Preserve the density-matrix (idempotency, norm) to first order when the NGWFs change. Only implemented for zero-temperature ground-state calculations.
    Default Value:

    False

    Example: kernel_christoffel_update T
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    KERNEL_CUTOFF

    Syntax: KERNEL_CUTOFF [Value] [Unit]
    Description: Specifies the density kernel spatial cutoff. Matrix elements are only included if the corresponding NGWF centres are closer than this distance.
    Default Value:

    1000.0 bohr; i.e. effectively infinite

    Example: kernel_cutoff 25.0 bohr
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    KERNEL_DIIS_COEFF

    Syntax: KERNEL_DIIS_COEFF [Real]
    Description: Fraction of the output density kernel or Hamiltonian matrix in the inner loop DIIS. Its value must be in the range [0,1]. Set to a negative number to enable the ODA method for calculating the optimum mixing parameter. References:

    E. Cancès, and C. Le Bris, Int. J. Quantum Chem. 79(2):82, 2000.


    E. Cancès, J. Chem. Phys. 114(24):10616, 2001.

    Default Value:

    0.1000

    Example: kernel_diis_coeff 0.2500
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    3.5.2.9

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    KERNEL_DIIS_CONV_CRITERIA

    Syntax: KERNEL_DIIS_CRITERIA [Text]
    Description: Set convergence criteria for inner loop diis. This input flag acts as a logical switch whose terms can only have the values 0 for false and 1 for true. Written as kernel_diis_criteria = wxyz, each component refers to:
     w : residual: sqrt[sum(K_{out} - K_{in})^2]
    
    x : [HKS,SKH] commutator
    y : delta energy gap (in Hartree)
    z : delta energy: E(n+1)-E(n) (in Hartree)

    Two or more elements activated means that the two criteria have to be true at the same time to achieve convergence (i.e. they have to be lower than kernel_diis_threshold).

    Default Value:

    1000

    Example: kernel_diis_conv_criteria 0110 (activates x and y but not w or z)
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    KERNEL_DIIS_LINEAR_ITER

    Syntax: KERNEL_DIIS_LINEAR_ITER [Integer]
    Description: Set the number of linear mixing iterations before activating Pulay, LiSTi or LiSTb mixing. The aim of these iterations is to generate a history of accurate density kernels to be used with the Pulay, LiSTi or LiSTb methods.
    Default Value:

    5

    Example: kernel_diis_linear_iter 10
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    KERNEL_DIIS_LSHIFT

    Syntax: KERNEL_DIIS_LSHIFT [Value] [Units]
    Description: Value of the shift in energy of the conduction bands with the level-shifting technique during the inner loop DIIS. Reference:

    V. R. Saunders, and I. H. Hillier, Int. J. Quantum Chem. 7(4):699, 1973.

    Default Value:

    1.0 hartree

    Example: kernel_diis_lshift: 1 eV
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    3.5.2.9

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    KERNEL_DIIS_LS_ITER

    Syntax: KERNEL_DIIS_LS_ITER [Integer]
    Description: Number of iterations of the inner loop DIIS method with level-shifting enabled.
    Default Value:

    0

    Example: kernel_diis_ls_iter: 5
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    KERNEL_DIIS_MAXIT

    Syntax: KERNEL_DIIS_MAXIT [Integer]
    Description: Maximum number of inner loop DIIS iterations
    Default Value:

    25

    Example: kernel_diis_maxit 40
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    KERNEL_DIIS_SCHEME

    Syntax: KERNEL_DIIS_SCHEME [Text]
    Description: Enable self-consistent density kernel or Hamiltonian mixing during the inner loop. Possible options:
    • NONE - no mixing - use LNV optimisation method instead.
    • DKN_LINEAR - linear mixing of density kernels.
    • HAM_LINEAR - linear mixing of Hamiltonians.
    • DKN_PULAY - Pulay mixing of density kernels.
    • HAM_PULAY - Pulay mixing of Hamiltonians.
    • DKN_LISTI - LiSTi mixing of density kernels.
    • HAM_LISTI - LiSTi mixing of Hamiltonians.
    • DKN_LISTB - LiSTb mixing of density kernels.
    • HAM_LISTB - LiSTb mixing of Hamiltonians.
    • DIAG - no mixing, only Hamiltonian diagonalisation. Not recommended.

    References:


    P. Pulay, Chem. Phys. Lett. 73(2):393, 1980.


    Y. A. Wang, C. Y. Yam, Y. K. Chen, and G. Chen, J. Chem. Phys. 134(24):241103, 2011


    Y. K. Chen, and Y. A. Wang, J. Chem. Theory Comput. 7(10):3045, 2011.

    Default Value:

    NONE

    Example: kernel_diis_scheme DKN_PULAY
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    KERNEL_DIIS_SIZE

    Syntax: KERNEL_DIIS_SIZE [Integer]
    Description: Maximum number of density kernel or Hamiltonian matrices that will be stored in memory. These kernels are then used with the Pulay, LiSTi or LiSTb schemes to generate the next input matrix. Warning: the more matrices are stored, the better the convergence will be, but also the more memory resources will be needed.
    Default Value:

    10

    Example: kernel_diis_size 25
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    KERNEL_DIIS_THRESHOLD

    Syntax: KERNEL_DIIS_THRESHOLD [Real]
    Description: Convergence threshold for the inner loop self-consistent optimisation. It acts for all active values of kernel_diis_conv_criteria.
    Default Value:

    1.0E-9

    Example: kernel_diis_thres 1.0e-7
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    KERNEL_UPDATE

    Syntax: KERNEL_UPDATE [Logical]
    Description: Update the density kernel when taking a trial step for NGWF optimization.
    Default Value:

    False

    Example: kernel_update T
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    KE_DENSITY_CALCULATE

    Syntax: KE_DENSITY_CALCULATE [Logical]
    Description: Calculate kinetic energy density.
    Default Value:

    False

    Example: ke_density_calculate T
    New in:

    5.1.6.13

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    K_ZERO

    Syntax: K_ZERO [Value] [Unit]
    Description: Specifies the kinetic energy preconditioning parameter. See Mostofi et al.,J. Chem. Phys.119, 8842 (2003) for further details.
    Default Value:

    3.0 bohr

    Example: k_zero 4.0 bohr
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    LATTICE_CART

    Syntax:

    %BLOCK LATTICE_CART
    a1x a1y a1z
    a2x a2y a2z
    a3x a3y a3z
    %ENDBLOCK LATTICE_CART

    Description: Specifies the lattice vectors a1, a2 and a3 for the simulation cell as Cartesian coordinates. By default, these will be interpreted as being in atomic units (a0), but they will be interpreted as being Angstroms if "ang" is on the first line of the block.
    Default Value:
    Example:

    %block lattice_cart
    7.500000 0.000000 0.000000 ; hexagonal unit cell with
    -3.750000 6.495191 0.000000 ; a = 7.5 a0
    0.000000 0.000000 9.000000 ; c = 9.0 a0
    %endblock lattice_cart

    or
    %block lattice_cart
    ang
    50.000000 0.000000 0.000000 ; large cubic cell
    0.000000 50.000000 0.000000 ;
    0.000000 0.000000 50.000000 ;
    %endblock lattice_cart


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    LIBXC_C_FUNC_ID

    Syntax: LIBXC_C_FUNC_ID [Integer]
    Description: Functional ID for the correlation functional (used in calculations employing the LIBXC library). The value of FUNCTIONAL must be set to LIBXC for this value to be accessed
    Default Value:

    0

    Example: libxc_c_func_id 13
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    LIBXC_X_FUNC_ID

    Syntax: LIBXC_X_FUNC_ID [Integer]
    Description: Functional ID for the exchange functional (used in calculations employing the LIBXC library). The value of FUNCTIONAL must be set to LIBXC for this value to be accessed
    Default Value:

    0

    Example: libxc_x_func_id 13
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    LNV_CG_MAX_STEP

    Syntax: LNV_CG_MAX_STEP [Value]
    Description: Maximum length of trial step for kernel optimisation line search
    Default Value:

    3.0

    Example: lnv_cg_max_step 10.0
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    LNV_CG_TYPE

    Syntax: LNV_CG_TYPE [Text]
    Description: Specifies the variant of the conjugate gradients algorithm used for the optimization of the density kernel, currently either LNV_FLETCHER for Fletcher-Reeves or LNV_POLAK for Polak-Ribiere.
    Default Value:

    LNV_FLETCHER

    Example: lnv_cg_type LNV_POLAK
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    LNV_CHECK_TRIAL_STEPS

    Syntax: LNV_CHECK_TRIAL_STEPS [Logical]
    Description: Activate checks on the stability of kernel at each trial step during LNV line search. Checks occupancy bounds and RMS occupancy error
    Default Value:

    True

    Example: lnv_check_trial_steps T
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    LNV_THRESHOLD_ORIG

    Syntax: LNV_THRESHOLD_ORIG [Real]
    Description: Specifies the convergence threshold for the RMS gradient of the density kernel.
    Default Value:

    1.0E-9

    Example: lnv_threshold_orig 1.0e-8
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    LOCPOT_SCHEME

    Syntax: LOCPOT_SCHEME [Text]
    Description: Scheme for evaluating local potential matrix elements. Possible values: FULL = Calculate matrix and symmetrize explicitly; LOWER = Calculate lower triangle elements only and infer upper triangle; ALTERNATE = Calculate alternating elements from both triangles and expand (fastest).
    Default Value:

    FULL

    Example: locpot_scheme ALTERNATE
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    LR_TDDFT_ANALYSIS

    Syntax: LR_TDDFT_ANALYSIS [Logical]
    Description: If the flag is set to True, a full cubic-scalling analysis of each TDDFT excitation is performed in which the response density is decomposed into dominant Kohn-Sham transitions.
    Default Value:

    False

    Example: lr_tddft_analysis True
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    LR_TDDFT_CG_THRESHOLD

    Syntax: LR_TDDFT_CG_THRESHOLD [Real]
    Description: The keyword specifi es the convergence tolerance on the sum of the n TDDFT excitation energies. If the sum of excitation energies changes by less than LR_TDDFT_CG_THRESHOLD in two consecutive iterations, the calculation is taken to be converged.
    Default Value:

    1.0E-6

    Example: lr_tddft_cg_threshold 5.0E-7
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    LR_TDDFT_JOINT_SET

    Syntax: LR_TDDFT_JOINT_SET [Logical]
    Description: If the flag is set to T, the joint NGWF set is used to represent the conduction space in the LR-TDDFT calculation.
    Default Value:

    True

    Example: lr_tddft_joint_set False
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    LR_TDDFT_KERNEL_CUTOFF

    Syntax: LR_TDDFT_KERNEL_CUTOFF [Value] [Unit]
    Description: Keyword sets a truncation radius on all response density kernels in order to
    achieve linear scaling computational eff ort with system size.
    Default Value:

    1000 bohr; virtually infinite

    Example: lr_tddft_kernel_cutoff 30.0 bohr
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    LR_TDDFT_MAXIG_CG

    Syntax: LR_TDDFT_MAXIT_CG [Integer]
    Description: The maximum number of conjugate gradient iterations the algorithm will perform.
    Default Value:

    60

    Example: lr_tddft_maxit_cg 100
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    LR_TDDFT_MAXIT_PEN

    Syntax: LR_TDDFT_MAXIT_PEN [Integer]
    Description: The maximum number purifi cation iterations performed per conjugate gradient step.
    Default Value:

    20

    Example: lr_tddft_maxit_pen 50
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    LR_TDDFT_NUM_STATES

    Syntax: LR_TDDFT_NUM_STATES [Integer]
    Description: The keyword specifi es how many excitations we want to converge. If set to a positive integer n, the TDDFT algorithm will converge the n lowest excitations of the system.
    Default Value:

    1

    Example: lr_tddft_num_states 10
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    LR_TDDFT_PENALTY_TOL

    Syntax: LR_TDDFT_PENALTY_TOL [Real]
    Description: Keyword sets a tolerance for the penalty functional. If the penalty functional is larger than LR_TDDFT_PENALTY_TOL, the algorithm will perform purifi cation iterations in order to decrease the penalty value and force towards the correct idempotency behaviour.
    Default Value:

    1.0E-8

    Example: lr_tddft_penalty_tol 5.0E-9
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    LR_TDDFT_PROJECTOR

    Syntax: LR_TDDFT_PROJECTOR [Logical]
    Description: If the flag is set to True, the conduction density matrix is redefi ned to be a projector onto the entire unoccupied subspace.
    Default Value:

    True

    Example: lr_tddft_projector False
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    LR_TDDFT_RESTART

    Syntax: LR_TDDFT_RESTART [Logical]
    Description: If the flag is set to True, the algorithm reads in LR_TDDFT_NUM_STATES response density kernels in .dkn format and uses them as initial trial vectors for a restarted LR-TDDFT calculation.
    Default Value:

    False

    Example: lr_tddft_restart True
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    LR_TDDFT_RPA

    Syntax: LR_TDDFT_RPA [Logical]
    Description: If the flag is set to True, a full TDDFT calculation in the so-called "Random Phase Approximation" will be performed, rather than invoking the Tamm-Dancoff approximation
    Default Value:

    False

    Example: lr_tddft_rpa True
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    LR_TDDFT_TRIPLET

    Syntax: LR_TDDFT_TRIPLET [Logical]
    Description: Flag that decides whether the LR_TDDFT_NUM_STATES states to be converged are singlet or triplet states.
    Default Value:

    False

    Example: lt_tddft_triplet T
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    LR_TDDFT_WRITE_DENSITIES

    Syntax: LR_TDDFT_WRITE_DENSITIES [Logical]
    Description: If the flag is set to True, the response density, electron density and hole density
    for each excitation is computed and written into a .cube file.
    Default Value:

    True

    Example: lr_tddft_write_densities False
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    LR_TDDFT_WRITE_KERNELS

    Syntax: LR_TDDFT_WRITE_KERNELS [Logical]
    Description: If the flag is set to T, the TDDFT response density kernels are printed out at every conjugate gradient iteration. These files are necessary to restart a LR-TDDFT calculation.
    Default Value:

    True

    Example: lr_tddft_write_kernels False
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    LUMO_DENS_PLOT

    Syntax: LUMO_DENS_PLOT [Integer]
    Description: Specifies the number of canonical orbitals above the LUMO to plot, if DO_PROPERTIES is set to true. Thus a value of zero plots only the LUMO, a negative value disables plotting and a positive value of N plots the N+1 lowest unoccupied canonical orbitals.
    Default Value:

    -1

    Example: lumo_dens_plot 0
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    LUMO_PLOT

    Syntax: LUMO_PLOT [Integer]
    Description: Specifies the number of canonical orbitals above the LUMO to plot, if DO_PROPERTIES is set to true. Thus a value of zero plots only the LUMO, a negative value disables plotting and a positive value of N plots the N+1 lowest unoccupied canonical orbitals.
    Default Value:

    5 ; plot the LUMO and the five canonical orbitals above

    Example: lumo_plot 0
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    MAXIT_CDFT_U_CG

    Syntax: MAXIT_CDFT_U_CG [Integer]
    Description: Specifies the maximum number of iterations for the constraining potentials (Uq/s) conjugate gradients optimisation.
    Default Value:

    60

    Example: maxit_cdft_u_cg 1
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    MAXIT_HOTELLING

    Syntax: MAXIT_HOTELLING [Integer]
    Description: Specifies the maximum number of iterations in the Hotelling algorithm used to invert the overlap matrix. See Ozaki,Phys. Rev. B.64, 195110 (2001) for more details. If MAXIT_HOTELLING is zero, then the inverse is computed using a traditional O(N^3) method.
    Default Value:

    50

    Example: maxit_hotelling 100
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    MAXIT_LNV

    Syntax: MAXIT_LNV [Integer]
    Description: Specifies the maximum number of iterations for the density kernel optimization.
    Default Value:

    5

    Example: maxit_lnv 3
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    MAXIT_NGWF_CG

    Syntax: MAXIT_NGWF_CG [Integer]
    Description: Specifies the maximum number of iterations for the NGWF conjugate gradients optimization.
    Default Value:

    60

    Example: maxit_ngwf_cg 25
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    MAXIT_PALSER_MANO

    Syntax: MAXIT_PALSER_MANO [Integer]
    Description: Specifies the maximum number of iterations for the Palser-Manolopoulos algorithm [Phys. Rev. B.58, 12704 (1998)] used to initialize the density kernel before the main optimization begins (when COREHAM_DENSKERN_GUESS is true, the default). If MAXIT_PALSER_MANO is negative then a traditionalO(N3) diagonalization is used.
    Default Value:

    50

    Example: maxit_palser_mano 30
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    MAXIT_PEN

    Syntax: MAXIT_PEN [Integer]
    Description: Specifies the maximum number of iterations for the penalty-functional algorithm [ Hayneset al.,Phys. Rev. B.59, 12173 (1999) ] used to refine the density kernel intialization before the main optimization begins. When reading the density kernel from disk this should normally be set to zero.
    Default Value:

    0

    Example: maxit_pen 5
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    MAX_RESID_HOTELLING

    Syntax: MAX_RESID_HOTELLING [Real]
    Description: Specifies the maximum residual allowed when inverting the overlap matrix by the Hotelling method. See Ozaki,Phys. Rev. B.64, 195110 (2001) for more details.
    Default Value:

    1e-12

    Example: max_resid_hotelling 1.0e-10
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    MD_DELTA_T

    Syntax: MD_DELTA_T [Value] [Unit]
    Description: Specifies the time step for molecular dynamics.
    Default Value:

    40 aut ; 40 atomic units of time

    Example: md_delta_t 1.0 fs
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    MD_NUM_ITER

    Syntax: MD_NUM_ITER [Integer]
    Description: Specifies the number of molecular dynamics steps.
    Default Value:

    100

    Example: md_num_iter 1000
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    MD_RESET_HISTORY

    Syntax: MD_RESET_HISTORY [Integer]
    Description: By default, in a molecular dynamics calculation, the initial guess for the electronic degrees of freedom is provided by the optimized NGWFs and density kernel from the previous time step. MD_RESET_HISTORY specifies the number of MD steps to be performed before the generation of new initial guesses for the NGWFs and density kernel. See MIX_DKN_TYPE and MIX_NGWFS_TYPE for more advanced mixing options.
    Default Value:

    100

    Example: md_reset_history 1000
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    MD_RESTART

    Syntax: MD_RESTART [Logical]
    Description: Restart the molecular dynamics calculation from previously generated backup files (i.e. *.md.restart and *.thermo.restart files).
    Default Value:

    False

    Example: md_restart T
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    MG_DEFCO_FD_ORDER

    Syntax: MG_DEFCO_FD_ORDER [Integer]
    Description: Order of finite differences to use in the high-order defect correction component of the multigrid solver. MG_DEFCO_FD_ORDER must be positive and even
    Default Value:

    2

    Example: mg_defco_fd_order 3
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    MG_GRANULARITY_POWER

    Syntax: MG_GRANULARITY_POWER [Integer]
    Description: Power of 2 which gives multigrid granularity, i.e. granularity = 2**N where N is MG_GRANULARITY_POWER. MG_GRANULARITY_POWER must be > 0.
    Default Value:

    3

    Example: mg_granularity_power 5
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    MG_TOL_RES_REL

    Syntax: MG_TOL_RES_REL
    Description: Relative tolerance in norm of residual for defect correction procedure in multigrid solver. MG_TOL_RES_REL must be >= 0.0.
    Default Value:

    1.0e-2

    Example: mg_tol_res_rel 1.0e-1
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    MINIT_LNV

    Syntax: MINIT_LNV [Integer]
    Description: Specifies the minimum number of iterations for the density kernel optimization.
    Default Value:

    5

    Example: minit_lnv 1
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    MIX_DKN_INIT_NUM

    Syntax: MIX_DKN_INIT_NUM [Integer]
    Description: Length of the initialization phase for the density kernel. Number of MD steps before the activation of the extrapolation/propagation scheme for building density kernel initial guesses.
    Default Value:

    0

    Example: mix_dkn_init_num 2
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    MIX_DKN_INIT_TYPE

    Syntax: MIX_DKN_INIT_TYPE [Text]
    Description: Specifies the mixing scheme used during the initialisation phase for the density kernel.
    • NONE : During the initialization phase, the initial density kernel is built according to COREHAM_DENSKERN_GUESS block.
      • REUSE : During the initialization phase, the density kernel from the last MD step is used as initial guess.
    Default Value:

    NONE

    Example: mix_dkn_init_type REUSE
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    MIX_DKN_NUM

    Syntax: MIX_DKN_NUM [Integer]
    Description: Number of density kernels required by the density kernel mixing scheme in order to generate the new initial guesses for the density kernel SCF process. See MIX_DKN_TYPE for a description of the available mixing schemes. The default depends on MIX_DKN_TYPE.
    Default Value:

    0

    Example: mix_dkn_num 2
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    MIX_DKN_RESET

    Syntax: MIX_DKN_RESET [Integer]
    Description: MIX_DKN_RESET specifies the number of MD steps to be performed before the generation of a new initial guess for the density kernel. See MIX_DKN_TYPE for more advanced mixing options.
    Default Value:

    50

    Example: mix_dkn_reset 100
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    MIX_DKN_TYPE

    Syntax: MIX_DKN_TYPE [Text]
    Description: Specifies the mixing scheme used to generate new initial guesses for the density kernel from the density kernels optimized at previous MD steps.
    • NONE : No use of MD history, initial density kernel is built according to COREHAM_DENSKERN_GUESS parameter.
    • REUSE : No kernel mixing. SCF density kernel at previous MD step is used as initial guess.
    • LINEAR : One dimensional linear extrapolation from density kernel at two previous MD steps.
    • MULTID : Multi-dimensional linear extrapolation from density kernel at previous MD steps. The dimension of the extrapolation space is determined by MIX_DKN_NUM.
    • POLY : One-dimensional polynomial extrapolation from density kernel at previous steps. The degree of the extrapolation polynom is determined by MIX_DKN_NUM.
    • PROJ : Projection of the previous SCF density kernel onto the set of extrapolated NGWFs. This option requires that MIX_NGWFS_TYPE is different than NONE.
    • TENSOR : Correction of the previous SCF density kernel in order to preserve tensorial integrity. This option requires that MIX_NGWFS_TYPE is different than NONE.
    • TRPROP : Time-reversible propagation of auxiliary density kernel.
    • DISSIP : Dissipative propagation of auxiliary density kernel. The number of previous MD steps used for the derivation of the dissipative force is determined by MIX_DKN_NUM
    Default Value:

    NONE

    Example: mix_dkn_type REUSE
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    MIX_LOCAL_LENGTH

    Syntax: MIX_LOCAL_LENGTH [Value] [Unit]
    Description: Specifies the localization length required by MIX_NGWFS_TYPE=3.
    Default Value:

    10.0 bohr

    Example: mix_local_length 15.0 bohr
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    MIX_LOCAL_SMEAR

    Syntax: MIX_LOCAL_SMEAR [Value] [Unit]
    Description: Allows to smear out the localization sphere used when MIX_NGWFS_TYPE=3.
    Default Value:

    5.0 bohr

    Example: mix_local_length 3.0 bohr
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    MIX_NGWFS_INIT_NUM

    Syntax: MIX_NGWFS_INIT_NUM [Integer]
    Description: Length of the initialization phase for NGWFs. Number of MD steps before the activation of the extrapolation/propagation scheme for building density kernel initial guesses.
    Default Value:

    0

    Example: mix_ngwfs_init_num 2
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    MIX_NGWFS_INIT_TYPE

    Syntax: MIX_NGWFS_INIT_TYPE [Text]
    Description: Specifies the mixing scheme used during the initialisation phase for the NGWFs.
    • NONE : During the initialization phase, initial NGWFs are built according to SPECIES_ATOMIC_SET block.
      • REUSE : During the initialization phase, NGWFs from the last MD step are used as initial guess.
    Default Value:

    NONE

    Example: mix_ngwfs_init_type REUSE
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    MIX_NGWFS_NUM

    Syntax: MIX_NGWFS_NUM [Integer]
    Description: Number of NGWFs sets required by the NGWFs mixing scheme in order to generate the new initial guesses for the NGWFs optimization process. See MIX_NGWFS_TYPE for a description of the available mixing schemes. Default depends on MIX_NGWFS_TYPE.
    Default Value:

    0

    Example: mix_ngwfs_num 2
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    MIX_NGWFS_RESET

    Syntax: MIX_NGWFS_RESET [Integer]
    Description: MIX_NGWFS_RESET specifies the number of MD steps to be performed before the generation of new initial guesses for the NGWFs. See MIX_NGWFS_TYPE for more advanced mixing options.
    Default Value:

    50

    Example: mix_ngwfs_reset 100
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    MIX_NGWFS_TYPE

    Syntax: MIX_NGWFS_TYPE [Text]
    Description: Specifies the mixing scheme used to generate new initial guesses for the NGWFs from the NGWFs optimized at previous MD steps.
    • NONE : No use of MD history, initial NGWFs are built according to the SPECIES_ATOMIC_SET block.
    • REUSE : No mixing of NGWFs. NGWFs from previous MD step are used as initial guess.
    • LINEAR : One dimensional linear extrapolation from NGWFs at two previous MD steps.
    • MULTID : Multi-dimensional linear extrapolation from NGWFs at previous MD steps. The dimension of the extrapolation space is determined by MIX_NGWFS_NUM.
    • POLY : One-dimensional polynomial extrapolation from NGWFs at previous steps. The degree of the extrapolation polynom is determined by MIX_NGWFS_NUM.
    • LOCAL : Generalized multi-dimensional linear extrapolation
      from NGWFs at previous steps. The dimension of the extrapolation space is determined by input parameter MIX_NGWFS_NUM. The localization radius
      is determine by input parameter MIX_LOCAL_LENGTH. Optionnally, the localization radius can be smeared out by using non-zero values for MIX_LOCAL_SMEAR.
    • TRPROP : Time-reversible propagation of auxiliary NGWFs.
    • DISSIP : Dissipative propagation of auxiliary NGWFs. The number of previous MD steps used for the derivation of the dissipative force is determined by MIX_NGWFS_NUM
    Default Value:

    NONE

    Example: mix_ngwfs_type REUSE
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    NBO_AOPNAO_SCHEME

    Syntax: NBO_AOPNAO_SCHEME [Text]
    Description: Thee AO to PNAO scheme to use. Affects the lm-averaging and diagonalisation steps in the initial AO to PNAO, NRB lm-averaging, and rediagonalisation transformations. For testing purposes only - so far none of the other schemes apart from ORIGINAL works. Possbile values are:
  • ORIGINAL - default, with lm-averaging
  • DIAGONALIZATION - Diagonalises entire atom-centred sub-block without lm-averaging or splitting between different angular channels.
  • NONE - Skips all rediagonalisation transformations.
  • Default Value:

    ORIGINAL

    Example: nbo_aopnao_scheme DIAGONALIZATION
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    NBO_INIT_LCLOWDIN

    Syntax: NBO_INIT_LCLOWDIN [Logical]
    Description: Performs atom-local Lowdin orthogonalisation on NGWFs as the first step before constructing NAOs.
    Default Value:

    True

    Example: nbo_init_lclowdin T
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    NBO_LIST_PLOTNBO

    Syntax:

    %BLOCK NBO_LIST_PLOTNBO
    GENNBO_orbital_index1
    GENNBO_orbital_index2
    ...
    GENNBO_orbital_indexN
    %ENDBLOCK NBO_LIST_PLOTNBO

    Description: The list of NBO_PLOT_ORBTYPE orbitals to be plotted, identified by their indices as in the gennbo output. Specify each index on a new line.
    Default Value:
    Example:

    GENNBO output indices specified on separate lines:


    %block nbo_list_plotnbo 
    
    8
    10
    %endblock nbo_list_plotnbo
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    NBO_PLOT_ORBTYPE

    Syntax: NBO_PLOT_ORBTYPE [Text]
    Description: The type of gennbo-generated orbitals to read and plot. Possible values and their associated gennbo
    transformation files must be present, as follows:
  • NAO - seedname_nao.33
  • NHO - seedname_nao.35
  • NBO - seedname_nao.37
  • NLMO - seedname_nao.39 ; NLMO is only defined for the full system i.e. partitioned FILE.47 will give meaningless NLMOs.

  • Except for NLMO, adding a "P" prefix e.g. "PNAO" to the value of NBO_PLOT_ORBTYPE causes the non-orthogonalised PNAOs to be used in plotting instead of NAOs. PNAOs are of the normal type, i.e. when RPNAO = F in gennbo (default).
  • Default Value:
    Example: nbo_plot_orbtype NAO
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    NBO_PNAO_ANALYSIS

    Syntax: NBO_PNAO_ANALYSIS [Logical]
    Description: Perform s/p/d/f analysis on the PNAOs (analogous to NGWF_ANALYSIS).
    Default Value:

    False

    Example: nbo_pnao_analysis T
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    NBO_SCALE_DM

    Syntax: NBO_SCALE_DM [Logical]
    Description: Scales partial density matrix output to seedname_nao_nbo.47 in order to achieve charge integrality.
    Default Value:

    True

    Example: nbo_scale_dm F
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    NBO_SCALE_SPIN

    Syntax: NBO_SCALE_SPIN [Logical]
    Description: Scales alpha and beta spins independently to integral charge when partial matrices are printed and NBO_SCALE_DM = T. Inevitably means spin density values from gennbo are invalid and one should calculate them manually from the NPA populations.
    Default Value:

    True

    Example: nbo_scale_spin F
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    NBO_SPECIES_NGWFLABEL

    Syntax:

    %BLOCK NBO_SPECIES_NGWFLABEL
    sub_region_atoms_1 "lm-label1"
    sub_region_atoms_2 "lm-label2"
    ...
    sub_region_atoms_N "lm-labelN"
    %ENDBLOCK NBO_SPECIES_NGWFLABEL

    Description: Optional user-defined (false) lm-label for NGWFs according to gennbo convention. "N" suffix denotes NMB orbital. If "SOLVE" orbitals are used, this block should be present, as "AUTO" initialisation assumes orbitals were also initialised as "AUTO".
    Default Value:

    AUTO

    Example:

    Species not specified will default to AUTO:


    %block nbo_species_ngwflabel 
    
    C1 "1N 151N 152N 153N"
    H1 "AUTO"
    %endblock nbo_species_ngwflabel
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    NBO_WRITE_DIPOLE

    Syntax: NBO_WRITE_DIPOLE [Logical]
    Description: Computes and writes dipole matrix to FILE.47
    Default Value:

    False

    Example: nbo_write_dipole T
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    NBO_WRITE_LCLOWDIN

    Syntax: NBO_WRITE_LCLOWDIN [Logical]
    Description: Writes full matrices (all atoms) in the atom-local Lowdin-orthogonalized basis to FILE.47 (For reference/testing/comparison purposes). Output will be seedname_lclowdin_nbo.47
    Default Value:

    False

    Example: nbo_write_lclowdin T
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    NBO_WRITE_NPACOMP

    Syntax: NBO_WRITE_NPACOMP [Logical]
    Description: Writes NAO charges for all orbitals to standard output.
    Default Value:

    False

    Example: nbo_write_npacomp T
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    NBO_WRITE_SPECIES

    Syntax:

    %BLOCK NBO_WRITE_SPECIES
    sub_region_atoms_1
    sub_region_atoms_2
    ...
    sub_region_atoms_N
    %ENDBLOCK NBO_WRITE_SPECIES

    Description: Block of lists of species to be included in the partial matrix output of seedname_nao_nbo.47. If not
    present all atoms will be included.
    Default Value:
    Example:

    If specified will default to AUTO:


    %block nbo_write_species 
    
    C1
    H1
    %endblock nbo_write_species
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    NEB_CI_DELAY

    Syntax: NEB_CI_DELAY [Integer]
    Description: Defines the number of BFGS steps the chain should take before enabling a climbing image. Negative numbers disable the climbing image entirely.
    Default Value:

    -1

    Example: neb_ci_delay 5
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    NEB_PRINT_SUMMARY

    Syntax: NEB_PRINT_SUMMARY [Boolean]
    Description: If True, ONETEP will print NEB convergence information as well as a summary of the reduced reaction coordinate and relative energy of each bead after each NEB step to the original stdout.
    Default Value:

    True

    Example: neb_print_summary F
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    NGWF_CG_MAX_STEP

    Syntax: NGWF_CG_MAX_STEP [Value]
    Description: Maximum length of trial step for NGWF optimisation line search. If NGWFS_CG_MAX_STEP is set to be negative, then NGWFS_CG_MAX_STEP = -NGWFS_CG_MAX_STEP * (CUTOFF_ENERGY / 22.04959837). For positive values, it is left unchanged.
    Default Value:

    -8.0

    Example: ngwf_cg_max_step 10.0
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    NGWF_CG_ROTATE

    Syntax: NGWF_CG_ROTATE [Logical]
    Description: Rotate the density kernel to the new NGWF representation after CG update. In EDFT calculations, it also rotates the eigenvectors.
    Default Value:

    False (True in EDFT)

    Example: ngwf_cg_rotate T
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    NGWF_CG_TYPE

    Syntax: NGWF_CG_TYPE [Text]
    Description: Specifies the variant of the conjugate gradients algorithm used for the optimization of the NGWFs, currently either NGWF_FLETCHER for Fletcher-Reeves or NGWF_POLAK for Polak-Ribiere.
    Default Value:

    NGWF_FLETCHER

    Example: ngwf_cg_type NGWF_POLAK
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    NGWF_HALO

    Syntax: NGWF_HALO [Real]
    Description: Specifies a halo size for the NGWFs to include matrix elements between NGWFs which do not directly overlap. In atomic units (a0). A negative value indicates that no halo should be used.
    Default Value:

    -1.0 ; no halo

    Example: ngwf_halo 1.0
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    NGWF_MAX_GRAD

    Syntax: NGWF_MAX_GRAD [Real]
    Description: Specifies the convergence threshold for the maximum value of the NGWF gradient at any psinc grid point. Ignored if negative.
    Default Value:

    -2.0E-5

    Example: ngwf_max_grad 1.0e-4
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    NGWF_THRESHOLD_ORIG

    Syntax: NGWF_THRESHOLD_ORIG [Real]
    Description: Specifies the convergence threshold for the RMS gradient of the NGWFs.
    Default Value:

    2.0E-6

    Example: ngwf_threshold_orig 1.0e-5
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    NNHO

    Syntax: NNHO [Logical]
    Description: Generate non-orthogonal natural hybrid orbitals from the NGWFs. See Fosteret al.,J. Am. Chem. Soc.102, 7211 (1980) for more details.
    Default Value:

    False

    Example: nnho T
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    NONSC_FORCES

    Syntax: NONSC_FORCES [Logical]
    Description: Calculates the residual non self-consistent forces due to the NGWF gradient.
    Default Value:

    True

    Example: nonsc_forces true
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    NUM_EIGENVALUES

    Syntax: NUM_EIGENVALUES [Integer]
    Description: Specifies the number of canonical orbital eigenvalues above and below the Fermi level to print when properties are required.
    Default Value:

    10

    Example: num_eigenvalues 5
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    NUM_IMAGES

    Syntax: NUM_IMAGES [Integer]
    Description: Defines the number of ONETEP instances that should run in parallel in the simulation and enables image-parallel mode. ONETEP must be run with MPI and the number of MPI processes must be divisible by the number of ONETEP images unless advanced specification is used. (see: image_sizes)

    In NEB, this is also the number of beads in the chain.
    Default Value:

    1

    Example: num_images 5
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    OCC_MIX

    Syntax: OCC_MIX [Real]
    Description: Specifies the fraction of the NGWF gradient to which occupancy preconditioning is applied.
    Default Value:

    0.25

    Example: occ_mix 1.0 ; fully preconditioned gradient
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    ODD_PSINC_GRID

    Syntax: ODD_PSINC_GRID [Logical]
    Description: Forces the simulation cell psinc grid to contain an odd number of points in each direction.
    Default Value:

    False

    Example: odd_osinc_grid T
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    OLD_LNV

    Syntax: OLD_LNV [Logical]
    Description: Enables backwards compatibility with legacy code.
    Default Value:

    False

    Example: old_lnv T
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    OPENBC_HARTREE

    Syntax: OPENBC_HARTREE [Logical]
    Description: Forces open boundary conditions in the calculation of the Hartree energy. These are automatically used whenever smeared ions (IS_SMEARED_ION_REP) are in use. This keyword can be used to force them in other (extremely rare) situations. It cannot be used to force them off.
    Default Value:

    False

    Example: OPENBC_HARTREE T
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    OPENBC_ION_ION

    Syntax: OPENBC_ION ION [Logical]
    Description: Forces open boundary conditions in the calculation of the ion-ion energy. These are automatically used whenever Martyna-Tuckerman (PBC_CORRECTION_CUTOFF), cutoff Coulomb (COULOMB_CUTOFF_TYPE) or smeared ions (IS_SMEARED_ION_REP) are in use. This keyword can be used to force them in other (extremely rare) situations. It cannot be used to force them off.
    Default Value:

    False

    Example: OPENBC_ION_ION T
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    OPENBC_PSPOT

    Syntax: OPENBC_PSPOT [Logical]
    Description: Forces open boundary conditions in the calculation of the local pseudopotential energy. These are automatically used whenever smeared ions (IS_SMEARED_ION_REP) are in use. This keyword can be used to force them in other (extremely rare) situations. It cannot be used to force them off.
    Default Value:

    False

    Example: OPENBC_PSPOT T
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    OPENBC_PSPOT_FINETUNE_ALPHA

    Syntax: OPENBC_PSPOT_FINETUNE_ALPHA [Value]
    Description: Sets the value of a numerical parameter (alpha) used in the calculation of the local pseudopotential in open boundary conditions. This parameter controls the transition between the short-range and long-range parts of the pseudopotential. Its impact on the total energy is negligible, provided it stays within reasonable bounds. Units of 1/bohr are implicitly assumed. This keyword is only relevant for calculations with open boundary conditions.
    Default Value:

    0.3

    Example: OPENBC_PSPOT_FINETUNE_ALPHA 0.5
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    OPENBC_PSPOT_FINETUNE_F

    Syntax: OPENBC_PSPOT_FINETUNE_F [INTEGER]
    Description: Sets the value of a unitless numerical parameter (grid fineness factor, f) used in the calculation of the local pseudopotential in open boundary conditions. This parameter controls the fineness of the reciprocal space radial grid used in the calculation. Its impact on the total energy is negligible, provided it stays within reasonable bounds. The default value of -1 causes f to be determined automatically -- this will generate a 'safe' value, making the grid as fine as necessary to have at least 50 sample g-points in any period of sin(gx) for the largest x in use in the calculation (the diagonal of the simulation cell). Thus, the automatically generated value depends on the cell size. Increasing this value makes little sense. Decreasing this value allows calculations to start faster, but decreases accuracy. This keyword is only relevant for calculations with open boundary conditions.
    Default Value:

    -1

    Example: OPENBC_PSPOT_FINETUNE_F 6
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    OPENBC_PSPOT_FINETUNE_NPTSX

    Syntax: OPENBC_PSPOT_FINETUNE_NPTS_X [INTEGER]
    Description: Sets the value of a unitless numerical parameter npts_x used in the calculation of the local pseudopotential in open boundary conditions. This parameter controls the number of points in the radial real-space grid on which the local pseudopotential is evaluated before interpolation to the 3D grid takes place. Increasing this value will offer marginal increase in accuracy at the expense of calculation wall time. This keyword is only relevant for calculations with open boundary conditions.
    Default Value:

    100000

    Example: OPENBC_PSPOT_FINETUNE_NPTS_X 500000
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    OUTPUT_DETAIL

    Syntax: OUTPUT_DETAIL [Text]
    Description: Specifies the level of detail in ONETEP's output: either BRIEF , NORMAL or VERBOSE .
    Default Value:

    NORMAL

    Example: output_detail VERBOSE
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    OVLP_FOR_NONLOCAL

    Syntax: OVLP_FOR_NONLOCAL [Logical]
    Description: Forces the nonlocal pseudopotential matrix and hence the Hamiltonian to have the sparsity pattern of the overlap matrix.
    Default Value:

    False

    Example: ovlp_for_nonlocal T
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    PADDED_LATTICE_CART

    Syntax:

    %BLOCK PADDED_LATTICE_CART
    a1x a1y a1z
    a2x a2y a2z
    a3x a3y a3z
    %ENDBLOCK PADDED_LATTICE_CART

    Description: Cutoff Coulomb only. Specifies the padded lattice vectors a1, a2 and a3 for the 'padded' simulation cell as Cartesian coordinates. By default, these will be interpreted as being in atomic units (a0), but they will be interpreted as being Angstroms if "ang" is on the first line of the block.
    Default Value:
    Example:

    %block padded_lattice_cart
    100.00000 0.00000 0.00000 ; cubic unit cell
    0.00000 100.00000 0.00000 ; side length 100 bohr
    0.00000 0.000000 100.00000 ;
    %endblock padded_lattice_cart

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    PAW

    Syntax: PAW [Logical]
    Description: Activates the Projector Augmented Wave Formalism: PAW potentials must then be supplied in the species_pot block.
    Default Value:

    False

    Example: PAW : T
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    PBC_CORRECTION_CUTOFF

    Syntax: PBC_CORRECTION_CUTOFF [Value] [Unit]
    Description: Turns on the Martyna-Tuckerman correction to the effects of periodic boundary conditions (PBCs), specifies the dimensionless cutoff parameter. A value of 7.0 is recommended by the authors in Martyna GJ and Tuckerman ME, J. Chem. Phys. 110, 2810 (1999), DOI:10.1063/1.477923.
    Default Value:

    0.0 bohr ; turned off

    Example: pbc_correction_cutoff 7.0 bohr
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    PEN_PARAM

    Syntax: PEN_PARAM [Real]
    Description: Specifies the energy parameter in hartrees for the penalty-functional algorithm [ Hayneset al.,Phys. Rev. B.59, 12173 (1999) ] used to refine the density kernel intialization before the main optimization begins.
    Default Value:

    4.0

    Example: pen_param 5.0
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    PHONON_ANIMATE_LIST

    Syntax:

    %BLOCK PHONON_ANIMATE_LIST
    mode_1
    mode_2
    ...
    mode_N
    %ENDBLOCK PHONON_ANIMATE_LIST

    Description: List of Gamma-point modes (where 1 is the lowest) for which to write xyz animation files.
    Default Value:

    Example:
    %block phonon_animate_list
    
    2
    6
    33
    34
    %endblock phonon_animate_list
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    PHONON_ANIMATE_SCALE

    Syntax: PHONON_ANIMATE_SCALE [Real]
    Description: Relative scale of the amplitude of the vibration in the xyz animation.
    Default Value:

    1.0

    Example: phonon_animate_scale 2.0
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    PHONON_DELTAT

    Syntax: PHONON_DELTAT [Value] [Unit]
    Description: Temperature step for the computation of thermodynamic quantities.
    Default Value:

    1.5E-5 Ha (~ 5K)

    Example: phonon_deltat 0.5E-5 Ha
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    PHONON_DISP_LIST

    Syntax:

    %BLOCK PHONON_DISP_LIST
    i_1
    i_2
    ...
    i_M (M smaller than/ equal to 3N)
    %ENDBLOCK PHONON_DISP_LIST

    Description: List of force constant calculations to perform for Stage 2 in phonon calculations (i.e. in the case of phonon_farming_task 2 or 0). Note that the total number of force constant calculations is given in the main output file in the line 'Number of force constants'; this will be less than or equal to 3N. The numbers listed in the phonon_disp_list block should go from 1 to this number; they can only be equated to the label 'i' if all 3N force constants are calculated. If unspecified, all displacements are performed.
    Default Value:

    Example:
    %block phonon_disp_list 
    
    1
    3
    5
    %endblock phonon_disp_list
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    PHONON_DOS

    Syntax: PHONON_DOS [Logical]
    Description: Calculate the phonon DOS and write to file.
    Default Value:

    True

    Example: phonon_dos F
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    PHONON_DOS_DELTA

    Syntax: PHONON_DOS_DELTA [Real]
    Description: Frequency step for the phonon DOS calculation (in 1/cm).
    Default Value:

    10.0

    Example: phonon_dos_delta 5.0
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    PHONON_DOS_MAX

    Syntax: PHONON_DOS_MAX [Real]
    Description: Upper bound of the phonon DOS range (in 1/cm).
    Default Value:

    1000.0

    Example: phonon_dos_max 1500.0
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    PHONON_DOS_MIN

    Syntax: PHONON_DOS_MIN [Real]
    Description: Lower bound of the phonon DOS range (in 1/cm).
    Default Value:

    0.0

    Example: phonon_dos_min 2.0
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    PHONON_ENERGY_CHECK

    Syntax: PHONON_ENERGY_CHECK [Logical]
    Description: Perform a sanity check that the total energy does not decrease upon ionic displacement.
    Default Value:

    False

    Example: phonon_energy_check T
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    PHONON_EXCEPTION_LIST

    Syntax:

    %BLOCK PHONON_EXCEPTION_LIST
    ion1 direction1 displacement_switch1 phonon_sampling1 factor_phonon_finite_disp1
    ion2 direction2 displacement_switch2 phonon_sampling2 factor_phonon_finite_disp2
    ...
    ionN directionN displacement_switchN phonon_samplingN factor_phonon_finite_dispN
    %ENDBLOCK PHONON_EXCEPTION_LIST

    Description: This is a block in which the user can list specific ion-coordinate pairs with options differing from the global defaults defined by PHONON_VIB_FREE, PHONON_SAMPLING, and PHONON_FINITE_DISP.
    Default Value:

    Example:

    In this example, we are overwriting the default PHONON_VIB_FREE, PHONON_SAMPLING, and PHONON_FINITE_DISP as such: the displacement of ion 10 in the z-direction (3) is switched on (1), with a value of phonon_sampling of 2, and a value of phonon_finite_disp of 0.9 times the global value; displacement of ion 15 in the x-direction (1) is switched off (0), with the last two parameters not being read; displacement of ion 36 in the y-direction (2) is switched off (0), with the last two parameters not being read.


    %block phonon_exception_list 
    
    10 3 1 2 0.9
    15 1 0 1 1.0
    36 2 0 1 1.0
    %endblock phonon_exception_list
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    PHONON_FARMING_TASK

    Syntax: PHONON_FARMING_TASK [Integer]
    Description: The most efficient way of performing a phonon calculation is by task farming, as the full force constants matrix is built up from many perturbed-structure calculations, each of which is completely independent. This can be done with the following steps:


    • Run phonon_farming_task 1 as a single job: this is essentially a standard single-point energy-and-force ONETEP calculation. Find the line in the main output file which gives the number of force constants needed for the phonon calculation you have specified (this will be between 1 and 3N)

    • Divide the total number of force constants that need to be calculated between the desired number of jobs. Prepare the ONETEP input file for each job specifying phonon_farming_task 2 and a subset of the force constant calculations in the PHONON_DISP_LIST block. Make sure every job has access to the files filename.dkn and filename.tightbox_ngwfs obtained from the unperturbed calculation in the previous step.

    • Collect all the filename.force_consts_i files and place them in the same directory. Finally, run phonon_farming_task 3 as a single job, to construct the full force constants matrix and perform the post-processing calculations.
    Default Value:

    0

    Example: phonon_farming_task 1
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    PHONON_FINITE_DISP

    Syntax: PHONON_FINITE_DISP [VALUE] [Unit]
    Description: Ionic displacement distance used in the finite-difference formula.
    Default Value:

    1.0E-1 bohr

    Example: phonon_finite_disp 5.0E-2 bohr
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    PHONON_FMAX

    Syntax: PHONON_FMAX [Value] [Unit]
    Description: Maximum ionic force allowed in the unperturbed system.
    Default Value:

    5.0E-3 'ha/bohr'

    Example: phonon_fmax 2.5E-3 'ha/bohr'
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    PHONON_GRID

    Syntax:

    %BLOCK PHONON_GRID
    factor_b1 factor_b2 factor_b3
    %ENDBLOCK PHONON_GRID

    Description: Definition of the regular grid of q-points used in phonon calculations for the computation of thermodynamic quantities and the phonon DOS. Default is 1 1 1 (i.e. Gamma point only).
    Default Value:

    1 1 1

    Example:

    In this example, we define a 10x10x10 sampling grid (over b1, b2 and b3 respectively), instead of the 1x1x1 default grid.


    %block phonon_grid 
    
    10 10 10
    %endblock phonon_grid
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    PHONON_MIN_FREQ

    Syntax: PHONON_MIN_FREQ [Value] [Unit]
    Description: Minimum phonon frequency for the computation of thermodynamic quantities, expressed as an energy; frequencies lower than this are discarded.
    Default Value:

    3.6E-6 Ha (~ 5 1/cm)

    Example: phonon_min_freq 2.0E-6 Ha
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    PHONON_QPOINTS

    Syntax:

    %BLOCK PHONON_QPOINTS
    frac-b1_1 frac-b2_1 frac-b3_1
    frac-b1_2 frac-b2_2 frac-b3_2
    ...
    frac-b1_N frac-b2_N frac-b3_N
    %ENDBLOCK PHONON_QPOINTS

    Description: List of additional q-points for which to calculate the phonon frequencies, in fractional coordinates of the reciprocal unit cell vectors. For non-supercell calculations only the Gamma point can be specified.
    Default Value:

    Example:
    %block phonon_qpoints 
    
    0.0 0.0 0.0
    0.0 0.0 0.1
    0.0 0.0 0.2
    0.0 0.0 0.3
    0.0 0.0 0.4
    0.0 0.0 0.5
    %endblock phonon_qpoints
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    PHONON_SAMPLING

    Syntax: PHONON_SAMPLING [Integer]
    Description: Selects which finite-difference formula to use. The elements of the force constants matrix are calculated by a central-difference formula, using either 2 (the default phonon_sampling 1) or 4 displacements (phonon_sampling 2). See documentation file for more information.
    Default Value:

    1

    Example: phonon_sampling 2
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    PHONON_SK

    Syntax: PHONON_SK [Logical]
    Description: Use a Slater-Koster style interpolation for q-points instead of a real-space cutoff of the force constants matrix elements.
    Default Value:

    False

    Example: phonon_sk T
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    PHONON_TMAX

    Syntax: PHONON_TMAX [Value] [Unit]
    Description: Upper bound of the temperature range for the computation of thermodynamic quantities.
    Default Value:

    2.0E-3 Ha

    Example: phonon_tmax 3.0E-3 Ha
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    PHONON_TMIN

    Syntax: PHONON_TMIN [Value] [Unit]
    Description: Lower bound of the temperature range for the computation of thermodynamic quantities, expressed as an energy (k_B T).
    Default Value:

    0.0 Ha

    Example: phonon_tmin 0.001 Ha
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    PHONON_VIB_FREE

    Syntax: PHONON_VIB_FREE [Integer]
    Description: This integer parameter controls the global default of which Cartesian directions are switched on for all ions. The options are: 0 (x=F y=F z=F), 1 (x=T y=F z=F), 2 (x=F y=T z=F), 3 (x=T y=T z=F), 4 (x=F y=F z=T), 5 (x=T y=F z=T), 6 (x=F y=T z=T) and 7 (x=T y=T z=T). The values in parenthesis explain which Cartesian direction (i.e. vibrational degree of freedom) is allowed.
    Default Value:

    7

    Example: phonon_vib_free 9
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    PHONON_WRITE_EIGENVECS

    Syntax: PHONON_WRITE_EIGENVECS [Logical]
    Description: Write the eigenvectors as well as the phonon frequencies to file for the additional q-points.
    Default Value:

    False

    Example: phonon_write_eigenvecs T
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    PLOT_NBO

    Syntax: PLOT_NBO [Logical]
    Description: Instructs ONETEP to read the relevant orbital transformation output from gennbo, determined by the flag NBO_PLOT_ORBTYPE and plots the orbitals specified in the NBO_LIST_PLOTNBO block. WRITE_NBO and PLOT_NBO are mutually exclusive. Scalar field plotting must be enabled (e.g. CUBE_FORMAT = T).
    Default Value:

    False

    Example: plot_nbo T
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    POLARISATION_CALCULATE

    Syntax: POLARISATION_CALCULATE [Logical]
    Description: Activates the calculation of polarisation
    Default Value:

    False

    Example: polarisation_calculate T
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    POLARISATION_SIMCELL_CALCULATE

    Syntax: POLARISATION_SIMCELL_CALCULATE [Boolean]
    Description: Turns on the calculation of polarisation in a properties calculation. Dipole moments and quadrupole moments are calculated for the entire system using the "simcell" approach (i.e. directly from integrals over real space). Both are calculated relative to a point defined by POLARISATION_SIMCELL_REFPT (default: 0.0 0.0 0.0).
    Default Value:

    F

    Example: polarisation_simcell_calculate T
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    POPN_BOND_CUTOFF

    Syntax: POPN_BOND_CUTOFF [Value] [Unit]
    Description: Specifies the bond length cutoff to use when performing Mulliken population analysis.
    Default Value:

    3 Angstroms

    Example: popn_bond_cutoff 5.0 ang
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    POPN_CALCULATE

    Syntax: POPN_CALCULATE [Logical]
    Description: Perform Mulliken population analysis.
    Default Value:

    True if DO_PROPERTIES is true, otherwise false.

    Example: popn_calculate F
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    POSITIONS_ABS

    Syntax:

    %BLOCK POSITIONS_ABS
    S1 R1x R1y R1z
    S2 R2x R2y R2z
    . . . .
    . . . .
    SN RNx RNy RNz
    %ENDBLOCK POSITIONS_ABS

    Description: Specifies the atomic positions as Cartesian coordinates). In the above syntax, Si denotes the species of atomi(max 4 characters) and Ri its position vector. Note that all atoms are currently required to be positioned within the simulation cell. By default, these will be interpreted as being in atomic units (a0), but they will be interpreted as being Angstroms if "ang" is on the first line of the block.
    Default Value:
    Example:

    %block positions_abs
    C 5.0 5.0 5.0 ; CO2 molecule
    O 2.7 5.0 5.0 ; centred in a cubic simulation cell
    O 7.3 5.0 5.0 ; with sides of 10 a0
    %endblock positions_abs

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    PPD_NPOINTS

    Syntax: PPD_NPOINTS [Text]
    Description: Specifies the size of the parallelepipeds (PPDs) used to group the simulation cell psinc grid points for efficiency. The size of the PPD is given by three integers corresponding to the number of grid points in the a1, a2 and a3 directions respectively. These integers must all be factors of the simulation cell psinc grid size in the relevant direction.
    Default Value:

    0 0 1 ; select automatically for a1 and a2 directions

    Example: ppd_npoints 5 7 6
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    PRECOND_REAL

    Syntax: PRECOND_REAL [Logical]
    Description: Apply kinetic energy preconditioning by a convolution in real-space. See Mostofiet al.,J. Chem. Phys.119, 8842 (2003) for further details.
    Default Value:

    False

    Example: precond_real T
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    PRECOND_RECIP

    Syntax: PRECOND_RECIP [Logical]
    Description: Apply kinetic energy preconditioning by a multiplication in reciprocal-space. See Mostofiet al.,J. Chem. Phys.119, 8842 (2003) for further details.
    Default Value:

    True

    Example: precond_recip F
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    PRECOND_SCHEME

    Syntax: PRECOND_SCHEME [Text]
    Description: Specifies the form of the kinetic energy preconditioner used, currently one of: BG - Bowler-Gillan scheme:Comput. Phys. Commun.112, 103 (1998) MAURI - Mauri scheme TETER - Teter-Payne-Allan scheme:Phys. Rev. B40, 12255 (1989) NONE - no kinetic energy preconditioning
    Default Value:

    TETER

    Example: precond_scheme MAURI
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    PRINT_QC

    Syntax: PRINT_QC [Text]
    Description: Include a summary of the calculation in the output for the purposes of "quality control" on code modifications.
    Default Value:

    False

    Example: print_qc T
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    PRODUCT_ENERGY

    Syntax: PRODUCT_ENERGY [Physical]
    Description: Both the reactant and product energies must be known at the start of a NEB calculation. The energy can be specified either as a raw total energy or as a rootname from which ONETEP can read the tightbox NGWF and density kernel (and, in EDFT, Hamiltonian) files from a previous calculation, or they can be calculated from scratch if neither is specified. The reactant and product energies needn’t be specified in the same way.

    This keyword specifies the total energy of the product.
    Default Value:

    N/A

    Example: product_energy -21102.843530 Ha
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    PRODUCT_ROOTNAME

    Syntax: PRODUCT_ROOTNAME [Text]
    Description: Both the reactant and product energies must be known at the start of a NEB calculation. The energy can be specified either as a raw total energy or as a rootname from which ONETEP can read the tightbox NGWF and density kernel (and, in EDFT, Hamiltonian) files from a previous calculation, or they can be calculated from scratch if neither is specified. The reactant and product energies needn’t be specified in the same way.

    This keyword specifies the rootname of the .tightbox_ngwf, .dkn, and/or .ham files that ONETEP can read the product from.
    Default Value:

    N/A

    Example: product_rootname my_prod_calculation
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    PROJECTORS_PRECALCULATE

    Syntax: PROJECTORS_PRECALCULATE [Text]
    Description: Controls whether the projectors are all evaluated in FFTboxes simultaneously, whenever the projector-NGWF overlap or projector gradient is required. If true, all projectors are evaluated at once (requiring many FFTboxes and significant memory usage if many projectors are present). If false, only one projector is evaluated at a time (which is slower, as new projectors must be re-evaluated many times over, but uses minimal memory).
    Default Value:

    True

    Example: projectors_precalculate F
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    PSINC_SPACING

    Syntax: PSINC_SPACING [Text]
    Description: Specifies the spacing between psinc grid points in the simulation cell by three real values (in atomic units a0) in the a1,a2 and a3directions respectively. These spacings must all be factors of the simulation cell lengths in the relevant directions. By default, these will be interpreted as being in atomic units (a0), but any recognised unit symbol can be used after the third value to override to a specific choice of units.
    Default Value:

    0.0 0.0 0.0 ; select automatically

    Example: psinc_spacing 0.4 0.5 0.5

    or

     psinc_spacing 0.25 0.25 0.25 ang 
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    REACTANT_ENERGY

    Syntax: REACTANT_ENERGY [Physical]
    Description: Both the reactant and product energies must be known at the start of a NEB calculation. The energy can be specified either as a raw total energy or as a rootname from which ONETEP can read the tightbox NGWF and density kernel (and, in EDFT, Hamiltonian) files from a previous calculation, or they can be calculated from scratch if neither is specified. The reactant and product energies needn’t be specified in the same way.

    This keyword specifies the total energy of the reactant.
    Default Value:

    N/A

    Example: neb_reactant_energy -21102.843530 Ha
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    REACTANT_ROOTNAME

    Syntax: REACTANT_ROOTNAME [Text]
    Description: Both the reactant and product energies must be known at the start of a NEB calculation. The energy can be specified either as a raw total energy or as a rootname from which ONETEP can read the tightbox NGWF and density kernel (and, in EDFT, Hamiltonian) files from a previous calculation, or they can be calculated from scratch if neither is specified. The reactant and product energies needn’t be specified in the same way.

    This keyword specifies the rootname of the .tightbox_ngwf, .dkn, and/or .ham files that ONETEP can read the reactant from.
    Default Value:

    N/A

    Example: reactant_rootname my_reac_calculation
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    READ_DENSKERN

    Syntax: READ_DENSKERN [Logical]
    Description: Read in the density kernel from disk. If the input filename is rootname.dat then the density kernel filename is rootname.denskern .
    Default Value:

    False

    Example: read_denskern T
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    READ_HAMILTONIAN

    Syntax: READ_HAMILTONIAN [Logical]
    Description: Read the Hamiltonian matrix from a .ham file. Currently, only used for restarting EDFT calculations.
    Default Value:

    False

    Example: read_hamiltonian F
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    READ_MAX_L

    Syntax: READ_MAX_L [Integer]
    Description: Specifies the maximum angular momentum of the spherical waves (l number) when reading from file.
    Default Value:

    3

    Example: read_max_l 5
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    READ_SW_NGWFS

    Syntax: READ_SW_NGWFS [Logical]
    Description: Read in the NGWFs from disk in spherical waves format and generates a linear combination of SW to restart the NGWFs. If the input filename is rootname.dat then the NGWFs filename is rootname.sw_ngwfs .
    Default Value:

    False

    Example: read_sw_ngwfs T
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    READ_TIGHTBOX_NGWFS

    Syntax: READ_TIGHTBOX_NGWFS [Logical]
    Description: Read in the NGWFs from disk. If the input filename is rootname.dat then the NGWFs filename is rootname.tightbox_ngwfs .
    Default Value:

    False

    Example: read_tightbox_ngwfs T
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    RMS_KERNEL_MEASURE

    Syntax: RMS_KERNEL_MEASURE [Logical]
    Description: Use a legacy measure of the commutator of the density-matrix and Hamiltonian, given by the root mean squared value of the doubly-covariant NGWF representation of their commutator.
    Default Value:

    False

    Example: rms_kernel_measure T
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    RUN_TIME

    Syntax: RUN_TIME [Real]
    Description: The maximum allocated run time for this job (in seconds). Certain iterative processes (NGWF CG, electronic transport etc) are timed on a per-iteration basis: if the timer detects that there is not enough time left before the total elapsed wall time reaches the value of run_time, then the iterative process will be halted to allow the code to exit gracefully.
    Default Value:

    -1 (no max run time)

    Example: run_time 43000
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    R_PRECOND

    Syntax: R_PRECOND [Value] [Unit]
    Description: Specifies the radius in atomic units (a0) of the real-space kinetic energy preconditioner (used to accelerate the convolution).
    Default Value:

    2.0 bohr

    Example: r_precond 1.5 bohr
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    SMOOTHING_FACTOR

    Syntax: SMOOTHING_FACTOR [Value]
    Description: The electronic volume Ve used in the electronic enthalpy method is obtained by using a Heaviside step function smeared by a smoothing factor [ corresponding to alpha/sigma in Corsini et al, J. Chem. Phys. 2013, 139, 084117] for numerical reasons.
    Default Value:

    5.0

    Example: smoothing_factor 6.0
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    SMOOTH_PROJECTORS

    Syntax: SMOOTH_PROJECTORS [Real]
    Description: Specifies the half-width in atomic units (a0) of a Gaussian filter used to smooth the nonlocal projectors. A negative value indicates that no smoothing should be applied.
    Default Value:

    -0.4 ; no smoothing

    Example: smooth_projectors 0.5
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    SOL_IONS

    Syntax:

    %BLOCK SOL_IONS
    species1 charge1 conc1
    species2 charge2 conc2
    ... ... ...
    speciesn chargen concn
    %ENDBLOCK SOL_IONS

    Description: Describes the kinds of Boltzmann ions in implicit solvent. Only relevant when solving the Poisson-Boltzmann equation in implicit solvent. Each entry specifies a name (species), charge and concentration (in mol/L).
    Default Value:

    (absent)

    Example:

    %block sol_ions
    Mg +2 0.1 ; MgCl2 @ 0.1 mol/L
    Cl -1 0.2
    %endblock sol_ions



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    SPECIES

    Syntax:

    %BLOCK SPECIES
    S1 X1 Z1 n1 R1
    S2 X2 Z2 n2 R2
    . . . . .
    . . . . .
    SN XN ZN nN RN
    %ENDBLOCK SPECIES

    Description: Defines the atomic species. In the above syntax, Si denotes the species of atom i(max 4 characters), corresponding to the element with symbol Xi and atomic number ZN , and with which are associated ni NGWFs of radius RN. More than one atomic species may refer to the same element, e.g. so that different ionic constraints may be applied to them. By default, the radii will be interpreted as being in atomic units (a0), but they will be interpreted as being Angstroms if "ang" is on the first line of the block.
    Default Value:
    Example:

    %block species
    C1 C 6 4 6.0 ; species C1 is carbon with 4 NGWFs of radius 6.0 a0
    C2 C 6 4 7.0 ; species C2 is also carbon but has 7.0 a0 NGWF radii
    H H 1 1 5.0 ; species H is hydrogen with 1 NGWF of radius 5.0 a0
    %endblock species

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    SPECIES_ATOMIC_SET

    Syntax:

    %BLOCK SPECIES_ATOMIC_SET
    S1 <Fireball filename 1> | AUTO | SOLVE
    S2 <Fireball filename 2> | AUTO | SOLVE
    . .. .
    %ENDBLOCK SPECIES_ATOMIC_SET

    Description: Specifies the set of initial atomic or pseudoatomic orbitals which will be used to initialise the NGWFs. One can either specify "fireball" (truncated pseudoatomic orbital) files,or use AUTO to generate STO-3G and 6-31G* basis functions, or one can use the built-in pseudoatomic solver, using "SOLVE". With "SOLVE", a configuration for the neutral pseudoatom is guessed on the basis of the ion charge and the atomic number, but this can be overridden. See the help file "pseudoatomic_solver.pdf" in the documentation folder (/doc in the distribution) for more information on how to use the pseudoatomic solver
    In the above syntax, Si denotes atomic species i(max 4 characters).

    automatically as required.

    Default Value:

    SOLVE for all species when this block is absent

    Example:

    %block species_atomic_set
    C1 C_01.fbl
    H SOLVE
    %endblock species_atomic_set

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    SPECIES_COND

    Syntax:

    %BLOCK SPECIES_COND
    S1 X1 Z1 n1 R1
    S2 X2 Z2 n2 R2
    . . . . .
    . . . . .
    SN XN ZN nN RN
    %ENDBLOCK SPECIES

    Description: Defines the atomic species used for conduction optimisation. The atomic species details must match those given in the SPECIES block, and the same guidelines apply. By default, the radii will be interpreted as being in atomic units (a0), but they will be interpreted as being Angstroms if "ang" is on the first line of the block.
    Default Value:
    Example:

    %block species
    C1 C 6 9 12.0 ; species C1 is carbon with 9 NGWFs of radius 12.0 a0
    C2 C 6 9 12.0 ; species C2 is also carbon but has 12.0 a0 NGWF radii
    H H 1 4 10.0 ; species H is hydrogen with 4 NGWFs of radius 10.0 a0
    %endblock species

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    SPECIES_CONSTRAINTS

    Syntax:

    %BLOCK SPECIES_CONSTRAINTS
    S1 NONE | FIXED | LINE | PLANE [C1x C1y C1z]
    . . . . .
    %ENDBLOCK SPECIES_CONSTRAINTS

    Description: Defines the constraints for the atomic species for use during geometry optimization. In the above syntax, Si denotes atomic speciesi(max 4 characters). The constraint type is one of NONE (no constraint), FIXED (atom is constrained to remain fixed), LINE (atom is constrained to a line) or PLANE (atom is constrained to a plane). In the case of LINE and PLANE , three further real values are required, to specify the direction vector of the line or the normal vector to the plane (in Cartesian coordinates) respectively.
    Default Value:
    Example:

    %block species_constraints
    C1 FIXED ; atoms of species C1 are fixed
    C2 LINE 1.0 0.0 0.0 ; atoms of species C2 can only move parallel to thex-axis
    H PLANE 0.0 0.0 1.0 ; atoms of species H can only move in thexy-plane
    %endblock species_constraints

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    SPECIES_LDOS_GROUPS

    Syntax:

    %BLOCK SPECIES_LDOS_GROUPS
    S1 S2 S3
    . . .
    %ENDBLOCK SPECIES_LDOS_GROUPS

    Description: Defines the groups of species identifiers for which the groups of an LDOS plot are defined. Each line defines a group with any number of entries allowed on the line. Species identifier labels must correspond to those defined in %block species.
    Default Value:
    Example:

    %block species_ldos_groups
    C1 H1 ; atoms of species C1 and H1 are in first group
    C2 H2 ; atoms of species C1 and H1 are in second group
    %endblock species_ldos_groups

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    SPECIES_NGWF_PLOT

    Syntax:

    %BLOCK SPECIES_NGWF_PLOT
    S1
    S2
    .
    %ENDBLOCK SPECIES_NGWF_PLOT

    Description: Defines the atomic species whose NGWFs are to be plotted during the calculation. In the above syntax, Si denotes atomic species i to plot.
    Default Value:
    Example:

    %block species_ngwf_plot
    C1
    C2
    H
    %endblock species_ngwf_plot

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    SPECIES_POT

    Syntax:

    %BLOCK SPECIES_POT
    S1 <Pseudopotential filename 1>
    S2 <Pseudopotential filename 2>
    . ..
    %ENDBLOCK SPECIES_POT

    Description: Specifies the pseudopotential files for the atomic species in a norm-conserving pseudopotential calculation, or the PAW potentials in a PAW Calculation. In the above syntax, Si denotes atomic species i (max 4 characters). Pseudopotential files can be in the CASTEP .recpot format or .usp format and must define norm-conserving pseudopotentials. PAW Potentials can be in the ABINIT .paw format.
    Default Value:
    Example:

    %block species_pot
    C1 C_01.recpot
    C2 C_00.recpot
    H H_01.recpot
    %endblock species_pot

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    SPIN

    Syntax: SPIN [Integer]
    Description: Specifies the total spin of the system in units of 1/2;h/(2pi). If the total spin is non-zero, a spin-polarized calculation will automatically be selected. Can be specified as a non-integer number in EDFT calculations.
    Default Value:

    0

    Example: spin 1
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    SPIN_POLARIZED

    Syntax: SPIN_POLARIZED [Logical]
    Description: Specifies that a spin-polarized calculation should be performed.
    Default Value:

    False, unless SPIN is non-zero, in which case True.

    Example: spin_polarized T
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    SPREAD_CALCULATE

    Syntax: SPREAD_CALCULATE [Text]
    Description: Activates the Calculation of NGWF spreads
    Default Value:

    False

    Example: spread_calculate T
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    SUPERCELL

    Syntax:

    %BLOCK SUPERCELL
    factor_a1 factor_a2 factor_a3
    ion1_base
    ...
    ionN_base
    %ENDBLOCK SUPERCELL

    Description: Within this block, the first line gives the shape of the supercell (2x2x2), and subsequent lines list the ions in the positions_abs_block that belong to the 'base' unit cell. When a supercell calculation is specified, only the ions within the unit cell are displaced, although the forces on all ions in the system are used to calculate the elements of the dynamical matrix. It is also possible to specify PHONON_VIB_FREE and PHONON_EXCEPTION_LIST in a supercell calculation, although only the ions listed in the supercell block can be included in the a href="#phonon_exception_list">PHONON_EXCEPTION_LIST block.
    Default Value:

    Example:

    In this example, we are defining a 2x2x2 supercell (for example for Si), with the ions of index 1 and 9 defining the "base" unit cell. Of course, a small supercell will not give sensible results for a phonon calculation. However, a good example would be a 1000-atom cubic supercell of Si, which gives excellent results.


    %block supercell
    2 2 2
    1
    9
    %endblock supercell
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    TASK

    Syntax: TASK [Text]
    Description: Specifies the task to be carried out, currently one of:
    SINGLEPOINT - single point energy calculation
    COND - Conduction NGWF optimisation calculation
    PROPERTIES - properties using results from a previous calculation of the ground state.
    PROPERTIES_COND - properties using results from a previous calculation of the conduction NGWFs.
    GEOMETRYOPTIMIZATION - geometry optimization using Cartesian or delocalized internal coordinates.
    MOLECULARDYNAMICS - molecular dynamics simulation.
    TRANSITIONSTATESEARCH - transition state search
    PHONON - a phonon frequencies and thermodynamics calculation.
    HUBBARDSCF - a projector-self-consistent DFT+U calculation.
    Default Value:

    SINGLEPOINT

    Example: task GEOMETRYOPTIMIZATION
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    THERMOSTAT

    Syntax:

    %BLOCK THERMOSTAT
    time_start1 time_stop1 thermo_type1 thermo_temp1
    option1 = value1 (optional)
    time_start2 time_stop2 thermo_type2 thermo_temp2
    option2 = value2 (optional)
    %ENDBLOCK THERMOSTAT

    Description: Defines the molecular dynamics thermostat. For each thermostat, the first line should contain the following mandatory parameters,
    • time_start (integer): the time step at which the thermostat is initialized;
    • time_stop (integer): the time step at which the thermostat is closed;
    • thermo_type (text): the kind of thermostat to be used, currently NONE, ANDERSEN, LANGEVIN, or NOSEHOOVER;
    • thermo_temp (physical): the thermostat temperature in physical units.

    Each thermostat may also be tuned using the options,

    • tgrad (physical)(Default = 0 K): Discrete variation of temperature T per MD step.
    • group (integer)(Default = 0): Index of the group of atoms (as de fined in
      POSITION_ABS) to which the
      thermostat is coupled. If no group of atoms is specfi ed, the thermostat is applied to the full system (i.e. group index 0).
    • tau (Physical)(Default = 10.0*MD_DELTA_T): Characteristic time scale of the thermostat. Depending on the type of thermostat, it may relate either to the average collision frequency or the thermostat fluctuation frequency or to the coupling with the heat bath;
    • damp (real)(Default = 0.2): Langevin damping parameter.
    • mix (real)(Default = 1.0): Collision amplitude of the Andersen thermostat.
    • nchain (integer)(Default = 0): Number of thermostats in the Nose-Hoover chain.
    • nstep (integer)(Default = 20): Number of substeps used to integrate the equation of motion of the Nose-Hoover coordinates.
    • update (logical)(Default = False): Impose to update the ef fective masses of the Nose-Hoover coordinates when the temperature is modi fied.
    Default Value:
    Example:

    Let us set an NVT calculation at 300K with Langevin thermostat for the equilibration (3000 steps) and Nose-Hoover thermostat for the thermodynamical sampling (10000 steps). The input parameters could look like.


    %block thermostat 
    
    1 3000 langevin 300.0 K
    damp = 0.2
    3001 13000 nosehoover 300.0 K
    nchain = 4
    tau = 800 aut
    %endblock thermostat
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    THREADS_MAX

    Syntax: THREADS_MAX [INTEGER]
    Description: Number of OpenMP threads in outer loops.
    Default Value:

    1 (may be changed at compilation or run-time).

    Example: threads_max 4
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    THREADS_NUM_FFTBOXES

    Syntax: THREADS_NUM_FFTBOXES [INTEGER]
    Description: Number of threads to use in OpenMP-parallel FFTs.
    Default Value:

    1 (may be changed at compilation or run-time).

    Example: threads_num_fftboxes 4
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    THREADS_NUM_MKL

    Syntax: THREADS_NUM_MKL [INTEGER]
    Description: The number of threads to use in MKL routines (matrix-matrix multiplications, inverses, diagonalisations etc.). ONETEP must be compiled against Intel's MKL library with the compile flag -DMKLOMP. Currently only used in the calculation of electron transmission.
    Default Value:

    1

    Example: threads_num_mkl 2
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    THREADS_PER_CELLFFT

    Syntax: THREADS_PER_CELLFFT [INTEGER]
    Description: Number of threads to use in OpenMP-parallel FFTs on simulation cell.
    Default Value:

    1

    Example: threads_per_cellfft 4
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    THREADS_PER_FFTBOX

    Syntax: THREADS_PER_FFTBOX [INTEGER]
    Description: Number of nested threads used for FFT box operations.

    This kind of threading requires an OpenMP-enabled version of the FFTW library. Otherwise, this functionality should be disabled via the FFTW3_NO_OMP compilation flag.
    Default Value:

    1

    Example: threads_per_fftbox 2
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    TIMINGS_LEVEL

    Syntax: TIMINGS_LEVEL [Integer]
    Description: Specifies the amount of detail in the timing information collected:0 - total time only reported1 - timings for routines averaged across all processors2 - timings for routines on all processors individually
    Default Value:

    1

    Example: timings_level 0
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    TSSEARCH_CG_MAX_ITER

    Syntax: TSSEARCH_CG_MAX_ITER [Integer]
    Description: Specifies the maximum number of conjugate gradients iterations for the transition state search.
    Default Value:

    20

    Example: tssearch_cg_max_iter 30
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    TSSEARCH_DISP_TOL

    Syntax: TSSEARCH_DISP_TOL [Value] [Unit]
    Description: Specifies atomic displacement tolerance used as one of the criteria for convergence of a transition state search. The positions of all atoms must change by less than this tolerance to satisfy this criterion.
    Default Value:

    0.01 bohr

    Example: tssearch_disp_tol 1.0e-3 nm
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    TSSEARCH_ENERGY_TOL

    Syntax: TSSEARCH_ENERGY_TOL [Value] [Unit]
    Description: Specifies the tolerance for enthalpy per atom over one NEB step for convergence.
    Default Value:

    1.0E-5 hartree

    Example: tssearch_energy_tol 0.2 meV
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    TSSEARCH_FORCE_TOL

    Syntax: TSSEARCH_FORCE_TOL [Value] [Unit]
    Description: Specifies the tolerance for maximum atomic force as a criterion for transition state search convergence. Note that units involving a forward slash (/) must be quoted as in the example below.
    Default Value:

    0.005 Ha/Bohr

    Example: tssearch_force_tol 0.05 'ev/ang'
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    TSSEARCH_LSTQST_PROTOCOL

    Syntax: TSSEARCH_LSTQST_PROTOCOL [Text]
    Description: Specifies the protocol for transition state search with the LSTQST method, currently one of LSTMAXIMUM , HALGREN-LIPSCOMB , LST/OPTIMIZATION , COMPLETELSTQST or QST/OPTIMIZATION .
    Default Value:

    LSTMAXIMUM

    Example: tssearch_lstqst_protocol LST/OPTIMIZATION
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    TSSEARCH_METHOD

    Syntax: TSSEARCH_METHOD [Text]
    Description: Specifies the method for transition state search, LSTQST or NEB. If NEB is used, NUM_IMAGES should also be specified to set the number of NEB beads.
    Default Value:

    LSTQST

    Example: tssearch_method NEB
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    TSSEARCH_QST_MAX_ITER

    Syntax: TSSEARCH_QST_MAX_ITER [Integer]
    Description: Specifies the maximum number of QST iterations for the transition state search.
    Default Value:

    5

    Example: tssearch_qst_max_iter 10
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    TURN_OFF_EWALD

    Syntax: TURN_OFF_EWALD [Boolean]
    Description: Elides the calculation of Ewald energy and force terms in the calculation. This is potentially useful in properties calculations, where the Ewald terms are known already from the singlepoint calculation and you don't want to spend time to recalculate them again.
    Default Value:

    F

    Example: turn_off_ewald T
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    USE_SPACE_FILLING_CURVE

    Syntax: USE_SPACE_FILLING_CURVE [Logical]
    Description: Use a Hilbert space-filling curve to distribute the atoms among processors in a parallel calculation.
    Default Value:

    True

    Example: use_space_filling_curve F
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    USE_SPH_HARM_ROT

    Syntax: USE_SPH_HARM_ROT [Boolean]
    Description: When True, manually activate the sph_harm_rotation (spherical harmonic rotation) module (used to evaluate the metric matrix in the 2Dn-1Da scheme for spherical wave metric matrix evaluation). In normal operation this is not necessary, since the module will be activated if it is detected that spherical harmonic rotation is required. Setting this to False has no effect, since the option will be overridden if ONETEP detects that the module is needed, anyway.
    Default Value:

    False

    Example: use_sph_harm_rot T
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    VDW_DCOEFF

    Syntax: VDW_DCOEFF [Real]
    Description: Overrides the damping constant associated with a damping function.
    Default Value:

    -1

    Example: vdw_dcoeff 11
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    VDW_PARAMS

    Syntax:
    %block vdw_params 
     nzatom_1 c6coeff_1 radzero_1 neff_1
     nzatom_2 c6coeff_2 radzero_2 neff_2
     ......
    %endblock vdw_params
    Description: This option allows the user to specify parameters for elements and functionals for which values are not given. The atom-dependent variables C6_i (used to calculate C6_ij),R0_i (related to the atomic vdW radius of an atom i), and n_eff (used in the calculation of C6_ij for all damping functions excluding the D2 correction of Grimme) are modified using the VDW_PARAMS block. This override block applies the parameter changes to atoms by their atomic number (nzatom).
    Default Value:
    Example:

    For example, to override the disp ersion parameters asso ciated with nitrogen:


    %block vdw_params 
    
    ! nzatom, c6coeff, radzero, neff
    7 21.1200 2.6200 2.51
    %endblock vdw_params
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    WRITE_CONVERGED_DK_NGWFS

    Syntax: WRITE_CONVERGED_DKNGWFS [Logical]
    Description: Specifies that the density kernel and NGWF output files should only be written at the end of a converged calculation, rather than after every iteration.
    Default Value:

    F

    Example: write_converged_dkngwfs T
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    WRITE_DENSITY_PLOT

    Syntax: WRITE_DENSITY_PLOT [Logical]
    Description: Specifies that the charge density, electrostatic potential and spin density (if appropriate) be written out for plottingif properties are requested.
    Default Value:

    True

    Example: write_density_plot F
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    WRITE_DENSKERN

    Syntax: WRITE_DENSKERN [Logical]
    Description: Write the density kernel to disk. If the input filename is rootname.dat then the density kernel filename is rootname.denskern .
    Default Value:

    True

    Example: write_denskern F
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    WRITE_FORCES

    Syntax: WRITE_FORCES [Logical]
    Description: Include the forces in the output of a single point energy calculation.
    Default Value:

    False

    Example: write_forces T
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    WRITE_HAMILTONIAN

    Syntax: WRITE_HAMILTONIAN [Logical]
    Description: Write the Hamiltonian matrix on a .ham file. Currently, only used in EDFT calculations. Set to true if a calculation is intended to be restarted at some point in the future.
    Default Value:

    False

    Example: write_hamiltonian T
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    WRITE_MAX_L

    Syntax: WRITE_MAX_L [Integer]
    Description: Specifies the maximum angular momentum of the spherical waves (l number) when writing to file.
    Default Value:

    3

    Example: write_max_l 2
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    WRITE_NBO

    Syntax: WRITE_NBO [Logical]
    Description: Enables Natural Population Analysis (NPA) and writing of gennbo input file seedname_nao_nbo.47
    Default Value:

    False

    Example: write_nbo T
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    WRITE_NGWF_PLOT

    Syntax: WRITE_NGWF_PLOT [Logical]
    Description: Write out NGWFs for species listed in the SPECIES_NGWF_PLOT to disk for plotting during a single point energy calculation, in the cube and/or .grd formats as requested.
    Default Value:

    False

    Example: write_ngwf_plot T
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    WRITE_SW_NGWFS

    Syntax: WRITE_SW_NGWFS [Logical]
    Description: Write the NGWFs to disk in spherical waves decomposition. If the input filename is rootname.dat then the NGWFs filename is rootname.sw_ngwfs .
    Default Value:

    False

    Example: write_sw_ngwfs T
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    WRITE_TIGHTBOX_NGWFS

    Syntax: WRITE_TIGHTBOX_NGWFS [Logical]
    Description: Write the NGWFs to disk. If the input filename is rootname.dat then the NGWFs filename is rootname.tightbox_ngwfs .
    Default Value:

    True

    Example: write_tightbox_ngwfs F
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    WRITE_XYZ

    Syntax: WRITE_XYZ [Logical]
    Description: Write the atom coordinates to disk as an .xyz file
    Default Value:

    False

    Example: write_xyz T
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    XC_FUNCTIONAL

    Syntax: XC_FUNCTIONAL [Text]
    Description: Specifies the exchange-correlation functional to use, currently one of:
    • LDA - default local (spin) density approximation, currently CAPZ
    • GGA - default generalized gradient approximation, currently RPBE
    • CAPZ - Perdew-Zunger parameterization [Phys. Rev. B 23, 5048 (1981)] of the Ceperley-Alder Monte Carlo data [Phys. Rev. Lett. 45, 566 (1980)] and Gell-Mann-Brueckner expansion [Phys. Rev. 106, 364 (1957)]
    • PW92 - Perdew and Wang 1992 LDA [Phys. Rev. B 45, 13244 (1992)]
    • VWN - Vosko, Wilk and Nusair parameterization [Phys. Rev. B 22, 3812 (1980)] of the LDA
    • PW91 - Perdew and Wang GGA [Phys. Rev. B 45, 13244 (1992)]
    • PBE - Perdew, Burke and Ernzerhof GGA [Phys. Rev. Lett. 77, 3865 (1996) and Erratum]
    • REVPBE - revised PBE by Zhang and Yang [Phys. Rev. Lett. 80, 890 (1998)]
    • RPBE - revised PBE by Hammer, Hansen and Norskov [Phys. Rev. B 59, 7413 (1999)]
    • PBESOL - revised PBE for solids by Perdew et al. [Phys. Rev. Lett. 100, 136406 (2008)]
    • BLYP -Becke 88 + LYP (Lee, Yang, Parr) GGA [Phys. Rev. A 38, 3098 (1988); Phys. Rev. B 37, 785 (1988)]
    • XLYP - Xu and Goddard GGA [PNAS 101, 2673 (2004)]
    • OPTB88 - X (OPTB88), C (LDA), vdW (vdW-DF 1) - J. Klimes et al. [J. Phys. Cond. Mat. 22 (2010)]
    • OPTPBE - X (OPTPBE), C (LDA), vdW (vdW-DF 1) - J. Klimes et al. [J. Phys. Cond. Mat. 22 (2010)]
    • VDWDF - X (revPBE), C (LDA), vdW (vdW-DF 1) - M. Dion et al. [Phys. Rev. Lett. (2004)]
    • VDWDF2 - X (rPW86), C (LDA), vdW (vdW-DF 2) - K. Lee et al. [Phys. Rev. B (2010)]
    • VV10 - X (rPW86), C (PBE), vdW (rVV10) - O. A. Vydrov et al. [J. Chem. Phys. (2010)]; R. Sabatini et al. [Phys. Rev. B (2013)]
    • AVV10S - X (AM05), C (AM05), vdW (rVV10-sol) - T. Bjorkman [Phys. Rev. B (2012)]
    Default Value:

    LDA

    Example: xc_functional PBE
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    ZERO_TOTAL_FORCE

    Syntax: ZERO_TOTAL_FORCE [Logical]
    Description: Forces the total ionic force to be zero by subtracting the average ionic force from all ionic forces.
    Default Value:

    True

    Example: zero_total_force F
    New in:

    3.5.2.16

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