Section XC

• Parameters needed for the calculation of the eXchange and Correlation potential

• Section path: CP2K_INPUT / FORCE_EVAL / DFT / ENERGY_CORRECTION / XC

• This section cannot be repeated.

• Subsections

  • ADIABATIC_RESCALING
  • GCP_POTENTIAL
  • HF
  • HFX_KERNEL
  • VDW_POTENTIAL
  • WF_CORRELATION
  • XC_FUNCTIONAL
  • XC_GRID
  • XC_KERNEL
  • XC_POTENTIAL

• Keywords

  • 2ND_DERIV_ANALYTICAL
  • 3RD_DERIV_ANALYTICAL
  • DENSITY_CUTOFF
  • DENSITY_SMOOTH_CUTOFF_RANGE
  • FUNCTIONAL_ROUTINE
  • GRADIENT_CUTOFF
  • NSTEPS
  • STEP_SIZE
  • TAU_CUTOFF

• Keyword descriptions

  2ND_DERIV_ANALYTICAL
  	2ND_DERIV_ANALYTICAL {Logical}
  	Use analytical formulas or finite differences for 2nd derivatives of XC
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .TRUE.

  3RD_DERIV_ANALYTICAL
  	3RD_DERIV_ANALYTICAL {Logical}
  	Use analytical formulas or finite differences for 3rd derivatives of XC
  	This keyword cannot be repeated and it expects precisely one logical.
  	The lone keyword behaves as a switch to .TRUE.
  	Default value: .TRUE.

  DENSITY_CUTOFF
  	DENSITY_CUTOFF {Real}
  	The cutoff on the density used by the xc calculation
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-010

  DENSITY_SMOOTH_CUTOFF_RANGE
  	DENSITY_SMOOTH_CUTOFF_RANGE {Real}
  	Parameter for the smoothing procedure inxc calculation
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 0.00000000E+000

  FUNCTIONAL_ROUTINE
  	FUNCTIONAL_ROUTINE {Keyword}
  	Select the code for xc calculation
  	This keyword cannot be repeated and it expects precisely one keyword.
  	Default value: DEFAULT
  	List of valid keywords: DEBUG Use debug new code for exchange-correlation functional calculation DEFAULT Carry out exchange-correlation functional calculation TEST_LSD Use test local-spin-density approximation code for exchange-correlation functional calculation

  GRADIENT_CUTOFF
  	GRADIENT_CUTOFF {Real}
  	The cutoff on the gradient of the density used by the xc calculation
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-010

  NSTEPS
  	NSTEPS {Integer}
  	Number of steps to consider in each direction for the numerical evaluation of XC derivatives. Must be a value from 1 to 4 (Default: 3).
  	This keyword cannot be repeated and it expects precisely one integer.
  	Default value: 3

  STEP_SIZE
  	STEP_SIZE {Real}
  	Step size in terms of the first order potential for the numerical evaluation of XC derivatives
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-003

  TAU_CUTOFF
  	TAU_CUTOFF {Real}
  	The cutoff on tau used by the xc calculation
  	This keyword cannot be repeated and it expects precisely one real.
  	Default value: 1.00000000E-010