- a converged SCF calculation
- the maximum core memory the program is allowed to allocate
should be defined in the data group
`$maxcor`(in MB); the recommended value is ca. 3/4 of the available (physical) core memory at most. - orbitals to be excluded from the correlation treatment have to
be specified in data group
`$freeze` - an auxiliary basis defined in the data group
`$cbas` - an auxiliary basis defined in the data group
`$jbas`for the computation of the Coulomb integrals for the Hartree-Fock energy - (optional) an auxiliary basis defined in the data group
`$jkbas`for the computation of the exchange integrals for the Hartree-Fock energy.`$rik`should be added to the control file for RI-JK to be effective.

The default number of grid points for the integration is 60, but may be changed by
adding the keyword `$rirpa` and the option `npoints` `n`

to the
control file, where `n`

is the number of grid points.
The computation of the
HXX energy can be skipped by adding the option `nohxx`.
Effective core potentials (ECPs) are not presently compatible with the
HXX energy as computed in `rirpa`.
The `nohxx` option *must* therefore be included
for systems where ECPs were used to obtain the reference KS orbitals in order
to skip the HXX energy calculation and compute solely the correlation energy.