DFOCC

Performs density-fitted orbital-optimized MPn and CC computations and conventional MPn computations.

General

CC_DIIS_MAX_VECS

Maximum number of vectors used in amplitude DIIS

  • Type: integer

  • Default: 6

CC_DIIS_MIN_VECS

Minimum number of vectors used in amplitude DIIS

  • Type: integer

  • Default: 2

CC_LAMBDA

Do solve lambda amplitude equations?

CC_MAXITER

Maximum number of iterations to determine the amplitudes

  • Type: integer

  • Default: 50

CHOLESKY

Do Cholesky decomposition of the ERI tensor

CHOLESKY_TOLERANCE

tolerance for Cholesky decomposition of the ERI tensor

COMPUT_S2

Do compute \(\langle \hat{S}^2 \rangle\) for DF-OMP2/DF-MP2?

CUTOFF

Cutoff value for numerical procedures

  • Type: integer

  • Default: 8

DO_DIIS

Do apply DIIS extrapolation?

DO_LEVEL_SHIFT

Do apply level shifting?

DO_SCS

Do perform spin-component-scaled OMP2 (SCS-OMP2)? In all computation, SCS-OMP2 energy is computed automatically. However, in order to perform geometry optimizations and frequency computations with SCS-OMP2, one needs to set ‘DO_SCS’ to true

DO_SOS

Do perform spin-opposite-scaled OMP2 (SOS-OMP2)? In all computation, SOS-OMP2 energy is computed automatically. However, in order to perform geometry optimizations and frequency computations with SOS-OMP2, one needs to set ‘DO_SOS’ to true

E3_SCALE

CEPA opposite-spin scaling value from SCS-CCSD

  • Type: double

  • Default: 0.25

EKT_IP

Do compute ionization potentials based on the extended Koopmans’ theorem?

E_CONVERGENCE

Convergence criterion for energy. See Table Post-SCF Convergence for default convergence criteria for different calculation types.

HESS_TYPE

Type of the MO Hessian matrix

  • Type: string

  • Possible Values: APPROX_DIAG, APPROX_DIAG_EKT, APPROX_DIAG_HF, HF

  • Default: HF

INTEGRAL_CUTOFF

Cutoff value for DF integrals

  • Type: integer

  • Default: 9

LEVEL_SHIFT

Level shift to aid convergence

  • Type: double

  • Default: 0.02

LINEQ_SOLVER

The solver will be used for simultaneous linear equations.

  • Type: string

  • Possible Values: CDGESV, FLIN, POPLE

  • Default: CDGESV

MAX_MOGRAD_CONVERGENCE

Convergence criterion for maximum orbital gradient. If this keyword is not set by the user, DFOCC will estimate and use a value required to achieve the desired E_CONVERGENCE The listed default will be used for the default value of E_CONVERGENCE

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.

MO_DIIS_NUM_VECS

Number of vectors used in orbital DIIS

  • Type: integer

  • Default: 6

MO_MAXITER

Maximum number of iterations to determine the orbitals

  • Type: integer

  • Default: 50

MO_STEP_MAX

Maximum step size in orbital-optimization procedure

  • Type: double

  • Default: 0.5

MP2_AMP_TYPE

The algorithm that used to handle mp2 amplitudes. The DIRECT option means compute amplitudes on the fly * whenever they are necessary.

  • Type: string

  • Possible Values: DIRECT, CONV

  • Default: DIRECT

MP2_OS_SCALE

MP2 opposite-spin scaling value

  • Type: double

  • Default: 6.0

MP2_SOS_SCALE

MP2 Spin-opposite scaling (SOS) value

  • Type: double

  • Default: 1.3

MP2_SOS_SCALE2

Spin-opposite scaling (SOS) value for optimized-MP2 orbitals

  • Type: double

  • Default: 1.2

MP2_SS_SCALE

MP2 same-spin scaling value

  • Type: double

  • Default: 1.0

NAT_ORBS

Do compute natural orbitals?

OCC_ORBS_PRINT

Do print OCC orbital energies?

OEPROP

Do compute one electron properties?

OO_SCALE

OO scaling factor used in MSD

  • Type: double

  • Default: 0.01

OPT_METHOD

The orbital optimization algorithm. Presently quasi-Newton-Raphson algorithm available with several Hessian * options.

  • Type: string

  • Possible Values: QNR

  • Default: QNR

ORB_OPT

Do optimize the orbitals?

ORB_RESP_SOLVER

The algorithm will be used for solving the orbital-response equations. The LINEQ option create the MO Hessian and solve the simultaneous linear equations with method choosen by the LINEQ_SOLVER option. The PCG option does not create the MO Hessian explicitly, instead it solves the simultaneous equations iteratively with the preconditioned conjugate gradient method.

  • Type: string

  • Possible Values: PCG, LINEQ

  • Default: PCG

ORTH_TYPE

The algorithm for orthogonalization of MOs

  • Type: string

  • Possible Values: GS, MGS

  • Default: MGS

PCG_BETA_TYPE

CEPA type such as CEPA0, CEPA1 etc. currently we have only CEPA0.

  • Type: string

  • Possible Values: FLETCHER_REEVES, POLAK_RIBIERE

  • Default: FLETCHER_REEVES

PCG_CONVERGENCE

Convergence criterion for residual vector of preconditioned conjugate gradient method. If this keyword is not set by the user, DFOCC will estimate and use a value required to achieve R_CONVERGENCE residual convergence. The listed default will be used for the default value of R_CONVERGENCE

PCG_MAXITER

Maximum number of preconditioned conjugate gradient iterations.

  • Type: integer

  • Default: 50

PPL_TYPE

Type of the CCSD PPL term.

  • Type: string

  • Possible Values: LOW_MEM, HIGH_MEM, CD, AUTO

  • Default: AUTO

QCHF

Do perform a QCHF computation?

READ_SCF_3INDEX

Do read 3-index integrals from SCF files?

REGULARIZATION

Do use regularized denominators?

REG_PARAM

Regularization parameter

  • Type: double

  • Default: 0.4

RMS_MOGRAD_CONVERGENCE

Convergence criterion for RMS orbital gradient. If this keyword is not set by the user, DFOCC will estimate and use a value required to achieve the desired E_CONVERGENCE The listed default will be used for the default value of E_CONVERGENCE

R_CONVERGENCE

Convergence criterion for amplitudes (residuals).

SCS_TYPE

Type of the SCS method

  • Type: string

  • Possible Values: SCS, SCSN, SCSVDW, SCSMI

  • Default: SCS

SOS_TYPE

Type of the SOS method

  • Type: string

  • Possible Values: SOS, SOSPI

  • Default: SOS

TRIPLES_IABC_TYPE

The algorithm to handle (ia|bc) type integrals that used for (T) correction.

  • Type: string

  • Possible Values: INCORE, AUTO, DIRECT, DISK

  • Default: DISK

WFN_TYPE

Type of the wavefunction.

  • Type: string

  • Default: DF-OMP2