** Next:** Diagnostics:
** Up:** CC2 Ground-State Energy Calculations
** Previous:** Ground-State calculations for other
** Contents**
** Index**

####

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 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

To activate in MP2 energy calculations evaluation of the diagnostic
use:
$ricc2
mp2 d1diag

TURBOMOLE