XC

Parameters needed for the calculation of the eXchange and Correlation potential [Edit on GitHub]

Keywords

Keyword descriptions

2ND_DERIV_ANALYTICAL

Type: logical
Default: T
Lone keyword: T
Usage: 2ND_DERIV_ANALYTICAL logical

Description: Use analytical formulas or finite differences for 2nd derivatives of XC [Edit on GitHub]

3RD_DERIV_ANALYTICAL

Type: logical
Default: F
Lone keyword: T
Usage: 3RD_DERIV_ANALYTICAL logical

Description: Use analytical formulas or finite differences for 3rd derivatives of XC [Edit on GitHub]

DENSITY_CUTOFF

Type: real
Default: 1.00000000E-010
Usage: density_cutoff 1.e-11

Description: The cutoff on the density used by the xc calculation [Edit on GitHub]

DENSITY_SMOOTH_CUTOFF_RANGE

Type: real
Default: 0.00000000E+000
Usage: DENSITY_SMOOTH_CUTOFF_RANGE {real}

Description: Parameter for the smoothing procedure in xc calculation [Edit on GitHub]

GRADIENT_CUTOFF

Type: real
Default: 1.00000000E-010
Usage: gradient_cutoff 1.e-11

Description: The cutoff on the gradient of the density used by the xc calculation [Edit on GitHub]

LIBXC_GPU_BACKEND

Type: enum
Default: HOST
Usage: LIBXC_GPU_BACKEND HOST

Description: Runtime device/host backend selection for LibXC. DEVICE selects the GPU backend (the default on GPU builds), HOST the CPU backend. DEVICE is an error (abort) when no usable GPU is found at runtime; HOST always runs. [Edit on GitHub]

Valid values:

  • DEVICE LibXC GPU backend

  • HOST LibXC CPU backend

NSTEPS

Type: integer
Default: 3
Usage: NSTEPS 4

Description: 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). [Edit on GitHub]

STEP_SIZE

Type: real
Default: 1.00000000E-003
Usage: STEP_SIZE 1.0E-3

Description: Step size in terms of the first order potential for the numerical evaluation of XC derivatives [Edit on GitHub]

TAU_CUTOFF

Type: real
Default: 1.00000000E-010
Usage: tau_cutoff 1.e-11

Description: The cutoff on tau used by the xc calculation [Edit on GitHub]