KPOINTS

Controls Brillouin-zone sampling with k-points. [Edit on GitHub]

Keywords

Keyword descriptions

DEBUG_FULL_KPOINT_SYMMETRY: logical = F

Lone keyword: T

Usage: DEBUG_FULL_KPOINT_SYMMETRY

Use full atomic k-point symmetry also for DEBUG finite-difference points. This is an expert option: the default keeps finite-difference energies on inversion/time-reversal symmetry to avoid comparing slightly different irreducible k-point sets. [Edit on GitHub]

EPS_SYMMETRY: real = 1.00000000E-006

Aliases: EPS_GEO

Usage: EPS_SYMMETRY

Accuracy in k-point symmetry determination. EPS_GEO is accepted as an alias. [Edit on GitHub]

FULL_GRID: logical = F

Lone keyword: T

Usage: FULL_GRID

Use the full, non-symmetry-reduced k-point grid. [Edit on GitHub]

GAMMA_CENTERED: logical = F

Lone keyword: T

Usage: GAMMA_CENTERED

Generate a gamma-centered variant of the Monkhorst-Pack or MacDonald mesh. This shifts the original mesh so it can include the Gamma point, and makes sense only when an even number of subdivisions is used. For MacDonald meshes, the explicit shift is applied after the gamma-centering shift. [Edit on GitHub]

INVERSION_SYMMETRY_ONLY: logical = F

Lone keyword: T

Usage: INVERSION_SYMMETRY_ONLY

Restrict k-point reduction to k-space inversion (time-reversal) symmetry. [Edit on GitHub]

KPOINT: real[4]

Keyword can be repeated.

Usage: KPOINT x y z w

Specify kpoint coordinates and weight. [Edit on GitHub]

PARALLEL_GROUP_SIZE: integer = -1

Usage: PARALLEL_GROUP_SIZE

Number of MPI processes to be used for a single k-point. This number must divide the total number of processes. The number of groups must divide the total number of kpoints. Value=-1 (smallest possible number of processes per group, satisfying the constraints). Value=0 (all processes). Value=n (exactly n processes). [Edit on GitHub]

SCHEME: string[ ]

Usage: SCHEME {KPMETHOD} {integer} {integer} ..

References: Monkhorst1976, MacDonald1978

K-point generation scheme. Available options are:

  • NONE

  • GAMMA

  • MONKHORST-PACK

  • MACDONALD

  • GENERAL

For MONKHORST-PACK the number of k points in all 3 dimensions has to be supplied along with the keyword. For MACDONALD also the list of shifts. E.g. MONKHORST-PACK 12 12 8, MACDONALD 4 4 4 0.25 0.25 0.25. GENERAL uses explicitly listed k-points. If symmetry reduction is requested, the explicit set must be equally weighted and closed under the selected operations. [Edit on GitHub]

SYMMETRY: logical = F

Lone keyword: T

Usage: SYMMETRY

Use symmetry to reduce the number of kpoints. [Edit on GitHub]

SYMMETRY_BACKEND: enum = K290

Usage: SYMMETRY_BACKEND K290

Valid values:

  • K290 Use the existing K290 k-point symmetry backend.

  • SPGLIB Use SPGLIB symmetry operations as k-point symmetry backend.

Select the backend used to provide and apply atomic k-point symmetry operations. K290 is the established default. SPGLIB uses the symmetry operations returned by SPGLIB, including their fractional translations. This applies to Monkhorst-Pack, MacDonald, and closed GENERAL k-point sets. If SYMMETRY_REDUCTION_METHOD is not specified, it follows the selected backend. [Edit on GitHub]

SYMMETRY_REDUCTION_METHOD: enum = K290

Usage: SYMMETRY_REDUCTION_METHOD K290

Valid values:

  • K290 Use the existing K290 k-point symmetry reduction method.

  • SPGLIB Use SPGLIB symmetry operations for k-point reduction.

Select the method used to reduce Monkhorst-Pack and MacDonald k-point meshes when atomic symmetry is enabled. K290 is the established default. SPGLIB uses the symmetry operations returned by SPGLIB for the k-point reduction. GENERAL k-point lists can be reduced when the explicit set is equally weighted and closed under the selected operations. With SYMMETRY_BACKEND K290 this can be used as a comparison mode using K290 operations for SPGLIB-generated mappings. [Edit on GitHub]

UNITS: string = B_VECTOR

Usage: UNITS

Special k-points are defined either in units of reciprocal lattice vectors or in Cartesian coordinates in units of 2Pi/len. B_VECTOR: in multiples of the reciprocal lattice vectors (b). CART_ANGSTROM: In units of 2Pi/Angstrom. CART_BOHR: In units of 2Pi/Bohr. [Edit on GitHub]

VERBOSE: logical = F

Lone keyword: T

Usage: VERBOSE

Verbose output information. [Edit on GitHub]

WAVEFUNCTIONS: enum = COMPLEX

Usage: WAVEFUNCTIONS REAL

Valid values:

  • REAL Use real wavefunctions (if possible by kpoints specified).

  • COMPLEX Use complex wavefunctions (default).

Select whether real or complex wavefunctions should be used when allowed by the k-point set. REAL wavefunctions can only represent Gamma or special k-points and symmetry operations with real Bloch phases. Use COMPLEX for general atomic k-point symmetries with nontrivial phases. [Edit on GitHub]