Fast RI-MP2 calculations with the RICC2 program:

The RICC2 program includes as a subset also the functionalities of the RI-MP2 program. Because of refined batching algorithms, screening and symmetry treatment the RICC2 program is usually somewhat faster than the RIMP2 program. This is in particular the cases in the following situations:

• when the molecular point group is $D_{2h}$ mathend000# or one of its subgroups and a significant number of atoms is positioned on symmetry elements (e.g. planar molecules)
• when because of memory restrictions the RIMP2 program needs many passes of the integral evaluation

All what is needed for a RI-MP2 gradient calculation with the RICC2 program is:

$ricc2
  geoopt model=mp2

If you want only the RI-MP2 energy for a single point use as input:

$ricc2
  mp2 energy only

The supplement energy only disables the calculation of intermediates for the residuum or vector function which are not needed to evaluate only the energy. But note that it will also disable the calculation of the $D_1$ mathend000# diagnostic (see below).