ACTIVE_SPACE

Define parameters and method to calculate an electronic active space [Edit on GitHub]

Keywords

Keyword descriptions

SECTION_PARAMETERS

Type: logical
Default: F
Lone keyword: T
Usage: &ACTIVE_SPACE ON

Description: Controls the activation of the ACTIVE_SPACE section

[Edit on GitHub]

ACTIVE_ELECTRONS

Type: integer
Default: -1
Usage: ACTIVE_ELECTRONS 4

Description: The number of active electrons in the CAS space

[Edit on GitHub]

ACTIVE_ORBITALS

Type: integer
Default: -1
Usage: ACTIVE_ORBITALS 2

Description: The number of active orbitals defining the CAS space.

[Edit on GitHub]

ACTIVE_ORBITAL_INDICES

Type: integer[ ]
Default: -1
Usage: ACTIVE_ORBITAL_INDICES 2 3 {…}

Description: The indices of the active orbitals. Requires ORBITAL_SELECTION MANUAL! Need to be as many indices as active orbitals times the number of spin channels (2 if ROKS or UKS/LSD else 1).

[Edit on GitHub]

ALPHA

Type: real
Default: 8.00000000E-001
Usage: ALPHA 0.25

Description: Fraction of new density to be mixed with previous one in SCF embedding. Kept for backwards compatibility; prefer ACTIVE_SPACE%MIXING%ALPHA.

[Edit on GitHub]

AS_SOLVER

Type: enum
Default: NONE
Usage: AS_SOLVER FCI

Description: The active space solver for the embedding approach

Valid values:

  • NONE NO solver, used to produce FCIDUMP/QCSchema files

  • QISKIT QISKIT active space solver

  • FCI LibFCI full-CI active space solver

[Edit on GitHub]

EPS_ITER

Type: real
Default: 1.00000000E-006
Usage: EPS_ITER 1.0E-6

Description: Energy convergence threshold of the DFT embedding scheme.

[Edit on GitHub]

MAX_ITER

Type: integer
Default: 50
Usage: MAX_ITER 50

Description: Max number of iterations for the DFT embedding scheme.

[Edit on GitHub]

ORBITAL_SELECTION

Type: enum
Default: CANONICAL
Usage: ORBITAL_SELECTION CANONICAL

Description: Method used to select active space orbitals.

Valid values:

  • CANONICAL Select orbitals using energy ordering of canoncial orbitals

  • WANNIER_PROJECTION Select orbitals from projected Wannier functions

  • MAO Select orbitals from modified atomic orbitals

  • MANUAL Select orbitals manually via ACTIVE_ORBITAL_INDICES

[Edit on GitHub]

QCSCHEMA

Type: string
Usage: QCSCHEMA

Description: Name of the QCSchema file, may include a path

[Edit on GitHub]

SCF_EMBEDDING

Type: logical
Default: F
Lone keyword: F

Description: Whether to turn on the self-consistent embedding scheme

[Edit on GitHub]

SUBSPACE_ATOM

Type: integer
Default: -1
Usage: SUBSPACE_ATOM x

Description: Number of atom that defines the subspace to be projected on.

[Edit on GitHub]

SUBSPACE_SHELL

Type: string
Default: X
Usage: SUBSPACE_SHELL 3d4s

Description: Shell definition for subsapce.

[Edit on GitHub]