SCF

Performs self consistent field (Hartree-Fock and Density Functional Theory) computations. These are the starting points for most computations, so this code is called in most cases.

General Wavefunction Info

BASIS

Primary basis set

  • Type: string

  • Possible Values: basis string

  • Default: No Default

CHOLESKY_TOLERANCE

Tolerance for Cholesky decomposition of the ERI tensor

DF_BASIS_SCF

Auxiliary basis set for SCF density fitting computations. Defaults to a JKFIT basis.

  • Type: string

  • Possible Values: basis string

  • Default: No Default

DF_SCF_GUESS

Do a density fitting SCF calculation to converge the orbitals before switching to the use of exact integrals in a SCF_TYPE DIRECT calculation

GUESS

The type of guess orbitals. Defaults to READ for geometry optimizations after the first step, to CORE for single atoms, and to SAD otherwise. The HUCKEL guess employs on-the-fly calculations like SAD, as described in doi:10.1021/acs.jctc.8b01089 which also describes the SAP guess.

  • Type: string

  • Possible Values: AUTO, CORE, GWH, SAD, SADNO, SAP, HUCKEL, READ

  • Default: AUTO

GUESS_MIX

Mix the HOMO/LUMO in UHF or UKS to break alpha/beta spatial symmetry. Useful to produce broken-symmetry unrestricted solutions. Notice that this procedure is defined only for calculations in C1 symmetry.

GUESS_PERSIST

If true, then repeat the specified guess procedure for the orbitals every time - even during a geometry optimization.

INTS_TOLERANCE

Screening threshold for the chosen screening method (SCHWARZ, CSAM, DENSITY) Absolute value below which TEI are neglected.

MAX_MEM_BUF

Max memory per buf for PK algo REORDER, for debug and tuning

  • Type: integer

  • Default: 0

MOLDEN_WRITE

Do write a MOLDEN output file? If so, the filename will end in .molden, and the prefix is determined by WRITER_FILE_LABEL (if set), or else by the name of the output file plus the name of the current molecule.

ORBITALS_WRITE

File name (case sensitive) to which to serialize Wavefunction orbital data.

  • Type: string

  • Default: No Default

QCHF

Do perform a QCHF computation?

REFERENCE

Reference wavefunction type. Cfour Interface: Keyword translates into CFOUR_REFERENCE

  • Type: string

  • Possible Values: RHF, ROHF, UHF, CUHF, RKS, UKS

  • Default: RHF

SAVE_JK

Keep JK object for later use?

SCF_MEM_SAFETY_FACTOR

Memory safety factor for allocating JK

  • Type: double

  • Default: 0.75

SCF_PROPERTIES

SCF Properties to calculate after an energy evaluation. Note, this keyword is not used for property evaluations.

  • Type: array

  • Default: No Default

S_CHOLESKY_TOLERANCE

Tolerance for partial Cholesky decomposition of overlap matrix.

S_ORTHOGONALIZATION

SO orthogonalization: automatic, symmetric, or canonical?

  • Type: string

  • Possible Values: AUTO, SYMMETRIC, CANONICAL, PARTIALCHOLESKY

  • Default: AUTO

S_TOLERANCE

Minimum S matrix eigenvalue to allow before linear dependencies are removed.

Convergence Control/Stabilization

BASIS_GUESS

Accelerate convergence by performing a preliminary SCF with this small basis set followed by projection into the full target basis. A value of TRUE turns on projection using the Defaults small basis set 3-21G, pcseg-0, or def2-SV(P).

  • Type: string

  • Default: FALSE

DAMPING_CONVERGENCE

The density convergence threshold after which damping is no longer performed, if it is enabled. It is recommended to leave damping on until convergence, which is the default. Cfour Interface: Keyword translates into CFOUR_SCF_DAMPING

DAMPING_PERCENTAGE

The amount (percentage) of damping to apply to the early density updates. 0 will result in a full update, 100 will completely stall the update. A value around 20 (which corresponds to 20% of the previous iteration’s density being mixed into the current density) could help to solve problems with oscillatory convergence.

  • Type: double

  • Default: 0.0

DF_BASIS_GUESS

When BASIS_GUESS is active, run the preliminary scf in density-fitted mode with this as fitting basis for the small basis set. A value of TRUE turns on density fitting with the default basis, otherwise the specified basis is used.

DIIS

Do use DIIS extrapolation to accelerate convergence?

DIIS_MAX_VECS

Maximum number of error vectors stored for DIIS extrapolation

  • Type: integer

  • Default: 10

DIIS_MIN_VECS

Minimum number of error vectors stored for DIIS extrapolation. Will be removed in v1.7.

  • Type: integer

  • Default: 2

DIIS_RMS_ERROR

Use RMS error instead of the more robust absolute error?

DIIS_START

The minimum iteration to start storing DIIS vectors and performing ADIIS/EDIIS.

  • Type: integer

  • Default: 1

D_CONVERGENCE

Convergence criterion for SCF density, defined as the RMS or maximum absolute value of the orbital gradient. See Table SCF Convergence & Algorithm for default convergence criteria for different calculation types. Cfour Interface: Keyword translates into CFOUR_SCF_CONV

E_CONVERGENCE

Convergence criterion for SCF energy. See Table SCF Convergence & Algorithm for default convergence criteria for different calculation types.

FAIL_ON_MAXITER

Fail if we reach maxiter without converging?

INCFOCK

Do perform incremental Fock build?

INCFOCK_CONVERGENCE

The density threshold at which to stop building the Fock matrix incrementally

INCFOCK_FULL_FOCK_EVERY

Frequency with which to compute the full Fock matrix if using INCFOCK . N means rebuild every N SCF iterations to avoid accumulating error from the incremental procedure.

  • Type: integer

  • Default: 5

LEVEL_SHIFT

Do use a level shift?

  • Type: double

  • Default: 0.0

LEVEL_SHIFT_CUTOFF

DIIS error at which to stop applying the level shift

  • Type: double

  • Default: 1e-2

MAXITER

Maximum number of iterations. Cfour Interface: Keyword translates into CFOUR_SCF_MAXCYC

  • Type: integer

  • Default: 100

MOM_OCC

The absolute indices of orbitals to excite from in MOM (+/- for alpha/beta)

  • Type: array

  • Default: No Default

MOM_START

The iteration to start MOM on (or 0 for no MOM)

  • Type: integer

  • Default: 0

MOM_VIR

The absolute indices of orbitals to excite to in MOM (+/- for alpha/beta)

  • Type: array

  • Default: No Default

SCF_INITIAL_ACCELERATOR

Use a method to accelerate initial SCF convergence? Use NONE for DIIS alone (if enabled) and EDIIS or ADIIS to have both the chosen accelerator and DIIS (if enabled). For restricted-open references, EDIIS and ADIIS have no effect.

  • Type: string

  • Possible Values: NONE, EDIIS, ADIIS

  • Default: ADIIS

SCF_INITIAL_FINISH_DIIS_TRANSITION

SCF error at which to complete the linear interpolation between DIIS steps and steps of the initial SCF accelerator Value taken from Garza and Scuseria, DOI: 10.1063/1.4740249

  • Type: double

  • Default: 1.0e-4

SCF_INITIAL_START_DIIS_TRANSITION

SCF error at which to start the linear interpolation between DIIS steps and steps of the initial SCF accelerator. Value taken from Garza and Scuseria, DOI: 10.1063/1.4740249

  • Type: double

  • Default: 1.0e-1

SOLVER_CONVERGENCE

Convergence threshold (max 2-norm) for numerical solvers (instability analysis and CPHF/CPKS).

SOLVER_MAXITER

Maximum iterations for numerical solvers (instability analysis and CPHF/CPKS).

  • Type: integer

  • Default: 100

SOLVER_N_GUESS

Number of guess vectors per root for instability analysis.

  • Type: integer

  • Default: 1

SOLVER_N_ROOT

Number of roots to converge for all irreps during instability analysis. (Overridden by SOLVER_ROOTS_PER_IRREP.)

  • Type: integer

  • Default: 1

SOLVER_ROOTS_PER_IRREP

Number of roots to converge, per irrep, during instability analysis. (Overrides SOLVER_N_ROOT.)

  • Type: array

  • Default: No Default

SOSCF

Do use second-order SCF convergence methods?

SOSCF_CONV

Second order convergence threshold. Cease microiterating at this value.

SOSCF_MAX_ITER

Maximum number of second-order microiterations to perform.

  • Type: integer

  • Default: 5

SOSCF_MIN_ITER

Minimum number of second-order microiterations to perform.

  • Type: integer

  • Default: 1

SOSCF_PRINT

Do we print the SOSCF microiterations?.

SOSCF_START_CONVERGENCE

When to start second-order SCF iterations based on gradient RMS.

STABILITY_ANALYSIS

Whether to perform stability analysis after convergence. NONE prevents analysis being performed. CHECK will print out the analysis of the wavefunction stability at the end of the computation. FOLLOW will perform the analysis and, if a totally symmetric instability is found, will attempt to follow the eigenvector and re-run the computations to find a stable solution.

  • Type: string

  • Possible Values: NONE, CHECK, FOLLOW

  • Default: NONE

Fractional Occupation UHF/UKS

FRAC_DIIS

Do use DIIS extrapolation to accelerate convergence in frac?

FRAC_LOAD

Do recompute guess from stored orbitals?

FRAC_OCC

The absolute indices of occupied orbitals to fractionally occupy (+/- for alpha/beta)

  • Type: array

  • Default: No Default

FRAC_RENORMALIZE

Do renormalize C matrices prior to writing to checkpoint?

FRAC_START

The iteration to start fractionally occupying orbitals (or 0 for no fractional occupation)

  • Type: integer

  • Default: 0

FRAC_VAL

The occupations of the orbital indices specified above (\(0.0\le {\rm occ} \le 1.0\))

  • Type: array

  • Default: No Default

Environmental Effects

EXTERN

An ExternalPotential (built by Python or nullptr/None)

ONEPOT_GRID_READ

Read an external potential from the .dx file?

PERTURB_DIPOLE

An array of length three describing the magnitude (atomic units) of the dipole field in the {x,y,z} directions

  • Type: array

  • Default: No Default

PERTURB_H

Do perturb the Hamiltonian?

PERTURB_MAGNITUDE

Size of the perturbation (applies only to dipole perturbations). Deprecated - use PERTURB_DIPOLE instead

  • Type: double

  • Default: 0.0

PERTURB_WITH

The operator used to perturb the Hamiltonian, if requested. DIPOLE_X, DIPOLE_Y and DIPOLE_Z will be removed in favor of the DIPOLE option in the future

  • Type: string

  • Possible Values: DIPOLE, DIPOLE_X, DIPOLE_Y, DIPOLE_Z, EMBPOT, SPHERE, DX

  • Default: DIPOLE

PHI_POINTS

Number of azimuthal grid points for spherical potential integration

  • Type: integer

  • Default: 360

RADIUS

Radius (bohr) of a hard-sphere external potential

  • Type: double

  • Default: 10.0

R_POINTS

Number of radial grid points for spherical potential integration

  • Type: integer

  • Default: 100

THETA_POINTS

Number of colatitude grid points for spherical potential integration

  • Type: integer

  • Default: 360

THICKNESS

Thickness (bohr) of a hard-sphere external potential

  • Type: double

  • Default: 20.0

DFSCF Algorithm

DF_BUMP_R0

Bump function min radius

  • Type: double

  • Default: 0.0

DF_BUMP_R1

Bump function max radius

  • Type: double

  • Default: 0.0

DF_DOMAINS

FastDF geometric fitting domain selection algorithm

  • Type: string

  • Possible Values: DIATOMIC, SPHERES

  • Default: DIATOMIC

DF_INTS_NUM_THREADS

Number of threads for integrals (may be turned down if memory is an issue). 0 is blank

  • Type: integer

  • Default: 0

DF_METRIC

FastDF Fitting Metric

  • Type: string

  • Possible Values: COULOMB, EWALD, OVERLAP

  • Default: COULOMB

DF_THETA

FastDF SR Ewald metric range separation parameter

  • Type: double

  • Default: 1.0

COSX Algorithm

COSX_INTS_TOLERANCE

Screening criteria for integrals and intermediates in COSX

COSX_RADIAL_POINTS_FINAL

Number of radial points in final COSX grid.

  • Type: integer

  • Default: 35

COSX_RADIAL_POINTS_INITIAL

Number of radial points in initial COSX grid.

  • Type: integer

  • Default: 25

COSX_SPHERICAL_POINTS_FINAL

Number of spherical points in final COSX grid.

  • Type: integer

  • Default: 110

COSX_SPHERICAL_POINTS_INITIAL

Number of spherical points in initial COSX grid.

  • Type: integer

  • Default: 50

SAD Guess Algorithm

SAD_D_CONVERGENCE

Convergence criterion for SCF density in the SAD guess, analogous to D_CONVERGENCE

SAD_E_CONVERGENCE

Convergence criterion for SCF energy in the SAD guess, analogous to E_CONVERGENCE

DFT

DFT_ALPHA

The DFT Exact-exchange parameter

  • Type: double

  • Default: 0.0

DFT_ALPHA_C

The DFT Correlation hybrid parameter

  • Type: double

  • Default: 0.0

DFT_BASIS_TOLERANCE

DFT basis cutoff.

DFT_BS_RADIUS_ALPHA

Factor for effective BS radius in radial grid.

  • Type: double

  • Default: 1.0

DFT_DISPERSION_PARAMETERS

Parameters defining the dispersion correction. See Table -D Functionals for default values and Table Dispersion Corrections for the order in which parameters are to be specified in this array option. Unused for functionals constructed by user.

  • Type: array

  • Default: No Default

DFT_GRAC_ALPHA

The gradient regularized asymptotic correction alpha value

  • Type: double

  • Default: 0.5

DFT_GRAC_BETA

The gradient regularized asymptotic correction beta value

  • Type: double

  • Default: 40.0

DFT_GRAC_SHIFT

The gradient regularized asymptotic correction shift value

  • Type: double

  • Default: 0.0

DFT_NUCLEAR_SCHEME

Nuclear Scheme.

  • Type: string

  • Possible Values: TREUTLER, BECKE, NAIVE, STRATMANN, SBECKE

  • Default: TREUTLER

DFT_OMEGA

The DFT Range-separation parameter

  • Type: double

  • Default: 0.0

DFT_OMEGA_C

The DFT Correlation Range-separation parameter

  • Type: double

  • Default: 0.0

DFT_PRUNING_SCHEME

Select approach for pruning. Options ROBUST and TREUTLER prune based on regions (proximity to nucleus) while FLAT P_GAUSSIAN D_GAUSSIAN P_SLATER D_SLATER LOG_GAUSSIAN LOG_SLATER prune based on decaying functions (experts only!). The recommended scheme is ROBUST.

  • Type: string

  • Default: NONE

DFT_RADIAL_POINTS

Number of radial points.

  • Type: integer

  • Default: 75

DFT_RADIAL_SCHEME

Radial Scheme.

  • Type: string

  • Possible Values: TREUTLER, BECKE, MULTIEXP, EM, MURA

  • Default: TREUTLER

DFT_SPHERICAL_POINTS

Number of spherical points (A Lebedev Points number).

  • Type: integer

  • Default: 302

DFT_SPHERICAL_SCHEME

Spherical Scheme.

  • Type: string

  • Possible Values: LEBEDEV

  • Default: LEBEDEV

DFT_V2_RHO_CUTOFF

Minima rho cutoff for the second derivative

  • Type: double

  • Default: 1.e-6

DFT_VV10_B

Define VV10 parameter b

  • Type: double

  • Default: 0.0

DFT_VV10_C

Define VV10 parameter C

  • Type: double

  • Default: 0.0

DFT_VV10_POSTSCF

post-scf VV10 correction

DFT_VV10_RADIAL_POINTS

Number of radial points for VV10 NL integration.

  • Type: integer

  • Default: 50

DFT_VV10_SPHERICAL_POINTS

Number of spherical points (A Lebedev Points number) for VV10 NL integration.

  • Type: integer

  • Default: 146

LOCAL_CONVERGENCE

The convergence on the orbital localization procedure

LOCAL_MAXITER

The maxiter on the orbital localization procedure

  • Type: integer

  • Default: 200

NL_DISPERSION_PARAMETERS

Parameters defining the -NL/-V dispersion correction. First b, then C

  • Type: array

  • Default: No Default

SAVE_UHF_NOS

Save the UHF NOs

UHF_NOONS

The number of NOONs to print in a UHF calc

  • Type: string

  • Default: 3

TDSCF

TDSCF_COEFF_CUTOFF

Cutoff for printing excitations and de-excitations contributing to each excited state

  • Type: double

  • Default: 0.1

TDSCF_GUESS

Guess type, only ‘denominators’ currently supported

  • Type: string

  • Default: DENOMINATORS

TDSCF_MAXITER

Maximum number of TDSCF solver iterations

  • Type: integer

  • Default: 60

TDSCF_PRINT

Verbosity level in TDSCF

  • Type: integer

  • Default: 1

TDSCF_R_CONVERGENCE

Convergence threshold for the norm of the residual vector. If unset, default based on D_CONVERGENCE

TDSCF_STATES

Number of roots (excited states) we should seek to converge. This can be either an integer (total number of states to seek) or a list (number of states per irrep). The latter is only valid if the system has symmetry. Furthermore, the total number of states will be redistributed among irreps when symmetry is used.

  • Type: array

  • Default: No Default

TDSCF_TDA

Run with Tamm-Dancoff approximation (TDA), uses random-phase approximation (RPA) when false

TDSCF_TDM_PRINT

Which transition dipole moments to print out: - E_TDM_LEN : electric transition dipole moments, length representation - E_TDM_VEL : electric transition dipole moments, velocity representation - M_TDM : magnetic transition dipole moments

  • Type: array

  • Default: No Default

TDSCF_TRIPLETS

Controls inclusion of triplet states, which is only valid for restricted references. Valid options: - none : No triplets computed (default) - also : lowest-energy triplets and singlets included, in 50-50 ratio. Note that singlets are privileged, i.e. if seeking to converge 5 states in total, 3 will be singlets and 2 will be triplets. - only : Only triplet states computed

  • Type: string

  • Possible Values: NONE, ALSO, ONLY

  • Default: NONE

WCOMBINE

combine omega exchange and Hartree–Fock exchange into one matrix for efficiency? Disabled until fixed.

Expert General Wavefunction Info

PK_ALGO

Select the PK algorithm to use. For debug purposes, selection will be automated later.

  • Type: string

  • Possible Values: REORDER, YOSHIMINE

  • Default: REORDER

PK_ALL_NONSYM

All densities are considered non symmetric, debug only.

PK_MAX_BUCKETS

Maximum numbers of batches to read PK supermatrix.

  • Type: integer

  • Default: 500

PK_NO_INCORE

Deactivate in core algorithm. For debug purposes.

WFN

Wavefunction type

  • Type: string

  • Possible Values: SCF

  • Default: SCF

Expert Convergence Control/Stabilization

FOLLOW_STEP_INCREMENT

When using STABILITY_ANALYSIS = FOLLOW, the increment to modify FOLLOW_STEP_SCALE value if we end up in the same SCF solution.

  • Type: double

  • Default: 0.2

FOLLOW_STEP_SCALE

When using STABILITY_ANALYSIS FOLLOW, how much to scale the step along the eigenvector by. A full step of \(pi/2\) corresponds to a value of 1.0.

  • Type: double

  • Default: 0.5

MAX_ATTEMPTS

When using STABILITY_ANALYSIS FOLLOW, maximum number of orbital optimization attempts to make the wavefunction stable.

  • Type: integer

  • Default: 1

Expert Parallel Runtime

DISTRIBUTED_MATRIX

The dimension sizes of the distributed matrix

  • Type: array

  • Default: No Default

PARALLEL

Do run in parallel?

PROCESS_GRID

The dimension sizes of the processor grid

  • Type: array

  • Default: No Default

TILE_SZ

The tile size for the distributed matrices

  • Type: integer

  • Default: 512

Expert Misc.

SAPT

Are going to do SAPT? If so, what part?

  • Type: string

  • Default: FALSE

Expert DFSCF Algorithm

DF_FITTING_CONDITION

Fitting Condition, i.e. eigenvalue threshold for RI basis. Analogous to S_TOLERANCE

  • Type: double

  • Default: 1.0e-10

DF_INTS_IO

IO caching for CP corrections, etc

  • Type: string

  • Possible Values: NONE, SAVE, LOAD

  • Default: NONE

Expert COSX Algorithm

COSX_BASIS_TOLERANCE

Screening criteria for basis function values on COSX grids

COSX_DENSITY_TOLERANCE

Screening criteria for shell-pair densities in COSX

COSX_OVERLAP_FITTING

Do reduce numerical COSX errors with overlap fitting?

COSX_PRUNING_SCHEME

Pruning scheme for COSX grids

  • Type: string

  • Default: ROBUST

Expert SAD Guess Algorithm

DF_BASIS_SAD

Density fitting basis used in SAD

  • Type: string

  • Possible Values: basis string

  • Default: SAD-FIT

SAD_CHOL_TOLERANCE

SAD guess density decomposition threshold

SAD_FRAC_OCC

Do force an even distribution of occupations across the last partially occupied orbital shell?

SAD_MAXITER

Maximum number of atomic SCF iterations within SAD

  • Type: integer

  • Default: 50

SAD_PRINT

The amount of SAD information to print to the output

  • Type: integer

  • Default: 0

SAD_SCF_TYPE

SCF type used for atomic calculations in SAD guess

  • Type: string

  • Possible Values: DIRECT, DF, MEM_DF, DISK_DF, PK, OUT_OF_CORE, CD, GTFOCK

  • Default: DF

SAD_SPIN_AVERAGE

Do use spin-averaged occupations instead of atomic ground spin state in fractional SAD?

Expert DFT

DFT_BLOCK_MAX_POINTS

The maximum number of grid points per evaluation block.

  • Type: integer

  • Default: 256

DFT_BLOCK_MAX_RADIUS

The maximum radius to terminate subdivision of an octree block [au].

  • Type: double

  • Default: 3.0

DFT_BLOCK_MIN_POINTS

The minimum number of grid points per evaluation block.

  • Type: integer

  • Default: 100

DFT_BLOCK_SCHEME

The blocking scheme for DFT.

  • Type: string

  • Possible Values: NAIVE, OCTREE, ATOMIC

  • Default: OCTREE

DFT_DENSITY_TOLERANCE

density cutoff for LibXC. A negative value turns the feature off and LibXC defaults are used.

DFT_GRAC_C_FUNC

The gradient regularized asymptotic correction functional corr form.

  • Type: string

  • Default: XC_LDA_C_VWN

DFT_GRAC_X_FUNC

The gradient regularized asymptotic correction functional exch form.

  • Type: string

  • Default: XC_GGA_X_LB

DFT_GRID_NAME

The DFT grid specification, such as SG1.

  • Type: string

  • Possible Values: SG0, SG1

  • Default: No Default

DFT_PRUNING_ALPHA

Spread alpha for logarithmic pruning.

  • Type: double

  • Default: 1.0

DFT_REMOVE_DISTANT_POINTS

Remove points from the quadrature grid that exceed the spatial extend of the basis functions.

DFT_VV10_RHO_CUTOFF

Rho cutoff for VV10 NL integration.

  • Type: double

  • Default: 1.e-8

DFT_WEIGHTS_TOLERANCE

grid weight cutoff. Disable with -1.0.