Section EXACT_EXCHANGE

• Whether exact-exchange should be added to the kernel and if so, with which fraction and operator.

• Section path: CP2K_INPUT / FORCE_EVAL / DFT / XAS_TDP / KERNEL / EXACT_EXCHANGE

• This section cannot be repeated.

• Subsections

  • RI_METRIC

• Keywords

  • SECTION_PARAMETERS
  • CUTOFF_RADIUS
  • EPS_RANGE
  • EPS_SCREENING
  • OMEGA
  • POTENTIAL_TYPE
  • SCALE
  • T_C_G_DATA

• Keyword descriptions

  SECTION_PARAMETERS
  	&EXACT_EXCHANGE {Logical}
  	Enables the addition of exact exchange to the kernel.
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .FALSE.

  CUTOFF_RADIUS
  	CUTOFF_RADIUS {Real}
  	The cutoff radius (in Angstrom) for the truncated Coulomb operator.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+000
  	Alias names for this keyword: R_C, RC, RANGE

  EPS_RANGE
  	EPS_RANGE {Real}
  	The threshold to determine the effective range of the short range operator: erfc(omega*eff_range)/eff_range = EPS_RANGE
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-006

  EPS_SCREENING
  	EPS_SCREENING {Real}
  	A threshold to determine which primitive 3-center integrals are kept for contraction, as the latter operation can be expensive (especially for large basis sets ).If |(ab|c)| < EPS_SCREENNING, it is discarded.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-008
  	Alias names for this keyword: EPS_SCREEN

  OMEGA
  	OMEGA {Real}
  	The range parameter for the short range operator (in 1/a0).
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+000

  POTENTIAL_TYPE
  	POTENTIAL_TYPE {Keyword}
  	The type of operator used for exact exchange. The standard Coulomb operator cannot be used in periodic systems.
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: COULOMB
  	List of valid keywords: COULOMB Standard Coulomb operator: 1/r SHORTRANGE Short range: erfc(omega*r)/r TRUNCATED Truncated Coulomb operator: 1/r if r < R_c, 0 otherwise
  	Alias names for this keyword: OP, OPERATOR, POTENTIAL

  SCALE
  	SCALE {Real}
  	Scaling of the exact exchange contribution.
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E+000
  	Alias names for this keyword: FRACTION

  T_C_G_DATA
  	T_C_G_DATA {Word}
  	Location of the file t_c_g.dat that contains the data for the evaluation of the truncated gamma function
  	This keyword cannot be repeated and it expects precisely one word.
  	Default value: t_c_g.dat