23.2 Coulomb-fitting MP2 (CF-MP2, RI-MP2)

Coulomb-fitting MP2 can be performed with standard density or and Poisson fitting basis sets. The present implementation works only without symmetry. The input is as follows:

CF-MP2,BASIS=basis_sets,[THRMP2_AO=thrao],[THRMP2_MO=thrmo],[THRMP2_OV=throv]

where

basis_sets:

Fitting basis sets, e.g., DENSITY for standard density fitting or DENSITY:POISSON for mixed density/Poisson fitting. These basis sets must have been defined in a previous BASIS block.

THRMP2_AO:

Screening threshold for 3-index integrals in the AO basis

THRMP2_MO:

Screening threshold for 3-index integrals in the MO basis

THRMP2_OV:

Screening threshold for overlap integrals of fitting basis.

RI-MP2 is an alias for the command CF-MP2. At present, expectation values and gradients cannot be computed with CF-MP2.