JDFTx  1.4.0
 All Classes Namespaces Files Functions Variables Typedefs Enumerations Enumerator Friends Macros Groups Pages
exchange-regularization

Syntax:

exchange-regularization <method>=AuxiliaryFunction|None|ProbeChargeEwald|SphericalTruncated|WignerSeitzTruncated

Description:

Regularization / singularity correction method for exact exchange. The allowed methods and defaults depend on the setting of <geometry> in command coulomb-interaction

  • None

    No singularity correction: default and only option for non-periodic systems with no G=0 singularity (<geometry> = Spherical / Isolated). This is allowed for fully or partially periodic systems, but is not recommended due to extremely poor convergence with number of k-points.

  • AuxiliaryFunction

    G=0 modification based on numerical integrals of an auxiliary function, as described in Ref. [4] Allowed for 3D/2D/1D periodic systems.

  • ProbeChargeEwald

    G=0 modification based on the Ewald sum of a single point charge per k-point sampled supercell. Valid for 3D/2D/1D periodic systems.

  • SphericalTruncated

    Truncate exchange kernel on a sphere whose volume equals the k-point sampled supercell, as in Ref. [26]. Allowed for any (partially) periodic <geometry>, but is recommended only when the k-point sampled supercell is roughly isotropic.

  • WignerSeitzTruncated

    Truncate exchange kernel on the Wigner-Seitz cell of the k-point sampled supercell, as in Ref. [27]. Default for any (partially) periodic <geometry>.

Properties:

Requires:     coulomb-interaction

Forbids:     (None)

Allow multiple:    no

Default:

exchange-regularization WignerSeitzTruncated

Back to: Input file documentation or Index of commands