EXCHANGE

Setup parameters for the evaluation of the EXCHANGE and core Hamiltonian terms in SE calculations. [Edit on GitHub]

Keywords

CUTOFF
RC_RANGE
RC_TAPER

Keyword descriptions

CUTOFF

Type: real
Default: 1.20000000E+001 [angstrom]
Usage: CUTOFF {real}

Description: Atomic Cutoff Radius Cutoff for the evaluation of the Exchange integrals. For non-periodic calculation the default value is exactly the full cell dimension, in order to evaluate all pair interactions. Instead, for periodic calculations the default is the minimum value between 1/4 of the cell dimension and the value specified in input (either explicitly defined or the default numerical value).

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RC_RANGE

Type: real
Default: 0.00000000E+000 [angstrom]
Usage: RC_RANGE {real}

Description: Range of cutoff switch function (tapering): 0.5*(1-TANH((r-r0)/RC_RANGE)), where r0=2.0RC_TAPER-20.0RC_RANGE.

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RC_TAPER

Type: real
Default: [angstrom]
Usage: RC_TAPER {real}

Description: Atomic Cutoff Radius Cutoff for Tapering Exchange integrals. If not specified it assumes the same value specified for the CUTOFF.

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