Section PERIODIC_CORRECTION

• Parameters influencing correction for periodic GW. Old method, not recommended to use

• Section path: CP2K_INPUT / FORCE_EVAL / DFT / ENERGY_CORRECTION / XC / WF_CORRELATION / RI_RPA / GW / PERIODIC_CORRECTION

• This section cannot be repeated.

• Subsections

  • none

• Keywords

  • AVERAGE_DEGENERATE_LEVELS
  • DO_AUX_BAS_GW
  • EPS_EIGENVAL
  • EPS_KPOINT
  • EXTRAPOLATE_KPOINTS
  • FRACTION_AUX_MOS
  • KPOINTS
  • MO_COEFF_GAMMA
  • NUM_KP_GRIDS
  • NUM_OMEGA_POINTS

• Keyword descriptions

  AVERAGE_DEGENERATE_LEVELS
  	AVERAGE_DEGENERATE_LEVELS {Logical}
  	If true, the correlation self-energy of degenerate levels is averaged.
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .TRUE.
  	Alias names for this keyword: ADL

  DO_AUX_BAS_GW
  	DO_AUX_BAS_GW {Logical}
  	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.
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  EPS_EIGENVAL
  	EPS_EIGENVAL {Real}
  	Threshold for considering levels as degenerate. Unit: Hartree.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 2.00000000E-004

  EPS_KPOINT
  	EPS_KPOINT {Real}
  	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.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-005

  EXTRAPOLATE_KPOINTS
  	EXTRAPOLATE_KPOINTS {Logical}
  	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.
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .TRUE.
  	Alias names for this keyword: EXTRAPOLATE

  FRACTION_AUX_MOS
  	FRACTION_AUX_MOS {Real}
  	Fraction how many MOs are used in the auxiliary basis.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 5.00000000E-001

  KPOINTS
  	KPOINTS {Integer} {Integer} {Integer}
  	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.
  	This keyword can be repeated and it expects precisely 3 integers.
  	Default values: 16 16 16

  MO_COEFF_GAMMA
  	MO_COEFF_GAMMA {Logical}
  	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.
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .TRUE.

  NUM_KP_GRIDS
  	NUM_KP_GRIDS {Integer}
  	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.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 1

  NUM_OMEGA_POINTS
  	NUM_OMEGA_POINTS {Integer}
  	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.
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 300