27.2 Density-fitting MP2 (DF-MP2, RI-MP2)

DF-MP2,options

invokes the density fitted MP2 program. The present implementation works only without symmetry. RI-MP2 is an alias for the command DF-MP2.

The following options can be specified:

BASIS_MP2=basis:

Fitting basis set. basis can either refer to a basis set defined in a BASIS block, or to a default fitting basis set (only available for correlation consistent basis sets). If a correlation consistent orbital basis set is used, the corresponding MP2 fitting basis is generated by default. In all other cases, the fitting basis must be defined.

THRAO=value:

Screening threshold for 3-index integrals in the AO basis

THRMO=value:

Screening threshold for 3-index integrals in the MO basis

THROV=value:

Screening threshold for 2-index integrals of fitting basis.

THRPROD=value:

Screening product threshold for first half transformation.

SPARSE=value:

If Non-zero, use sparse algorithm in second-half transformation (default).

See section 11 for a more general description of density fitting.

At present, expectation values and gradients cannot be computed with DF-MP2, but work with the local variant DF-LMP2.