KPOINTS

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

Keywords

Keyword descriptions

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]

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 the explicitly listed k-points as supplied and does not apply SYMMETRY_BACKEND or SYMMETRY_REDUCTION_METHOD. [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 and MacDonald meshes. For GENERAL, the explicit k-point list is used as supplied. 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 are not reduced. 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]