23.7 Density-fitting MP2 (DF-MP2, RI-MP2)
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:
- 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.
- Screening threshold for 3-index integrals in the AO basis
- Screening threshold for 3-index integrals in the MO basis
- Screening threshold for 2-index integrals of fitting basis.
- Screening product threshold for first half transformation.
- If Non-zero, use sparse algorithm in second-half transformation (default).
See section 15 for a more general description of density fitting. Expectation values and
gradients can also be computed with DF-MP2.