PERIODIC_CORRECTION

Parameters influencing correction for periodic GW. Old method, not recommended to use [Edit on GitHub]

Keywords

Keyword descriptions

AVERAGE_DEGENERATE_LEVELS

Type: logical
Default: T
Aliases: ADL
Lone keyword: T
Usage: AVERAGE_DEGENERATE_LEVELS

Description: If true, the correlation self-energy of degenerate levels is averaged.

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DO_AUX_BAS_GW

Type: logical
Default: F
Lone keyword: T
Usage: DO_AUX_BAS_GW TRUE

Description: If true, use a different basis for the periodic correction. This can be necessary in case a diffused basis is used for GW to converge the HOMO-LUMO gap. In this case, numerical problems may occur due to diffuse functions in the basis. This keyword only works if AUX_GW is specified in the kind section for every atom kind.

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EPS_EIGENVAL

Type: real
Default: 2.00000000E-004
Usage: EPS_EIGENVAL 1.0E-5

Description: Threshold for considering levels as degenerate. Unit: Hartree.

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EPS_KPOINT

Type: real
Default: 1.00000000E-005
Usage: EPS_KPOINT 1.0E-4

Description: If the absolute value of a k-point is below EPS_KPOINT, this kpoint is neglected since the Gamma point is not included in the periodic correction.

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EXTRAPOLATE_KPOINTS

Type: logical
Default: T
Aliases: EXTRAPOLATE
Lone keyword: T
Usage: EXTRAPOLATE_KPOINTS FALSE

Description: If true, extrapolates the k-point mesh. Only working if k-point mesh numbers are divisible by 4, e.g. 8x8x8 or 12x12x12 is recommended.

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FRACTION_AUX_MOS

Type: real
Default: 5.00000000E-001
Usage: FRACTION_AUX_MOS 0.6

Description: Fraction how many MOs are used in the auxiliary basis.

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KPOINTS

Type: integer[3]
Default: 16 16 16
Repeatable: yes
Usage: KPOINTS nx ny nz

Description: Specify number of k-points for a single k-point grid. Internally, a Monkhorst-Pack grid is used. Typically, even numbers are chosen such that the Gamma point is excluded from the k-point mesh.

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MO_COEFF_GAMMA

Type: logical
Default: T
Lone keyword: T
Usage: MO_COEFF_GAMMA

Description: If true, only the MO coefficients at the Gamma point are used for the periodic correction. Otherwise, the MO coeffs are computed at every k-point which is much more expensive. It should be okay to use the Gamma MO coefficients.

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NUM_KP_GRIDS

Type: integer
Default: 1
Usage: NUM_KP_GRIDS 5

Description: Number of k-point grids around the Gamma point with different resolution. E.g. for KPOINTS 4 4 4 and NUM_KP_GRIDS 3, there will be a 3x3x3 Monkhorst-Pack (MP) k-point grid for the whole Brillouin zone (excluding Gamma), another 3x3x3 MP grid with smaller spacing around Gamma (again excluding Gamma) and a very fine 4x4x4 MP grid around Gamma.

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NUM_OMEGA_POINTS

Type: integer
Default: 300
Usage: NUM_OMEGA_POINTS 200

Description: Number of Clenshaw-Curtis integration points for the periodic correction in cubic- scaling GW. This variable is a dummy variable for canonical N^4 GW calculations.

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