Preliminaries

All response calculations require a complete set of converged (occupied and virtual) SCF MOs. It is strongly recommended to use well converged MOs, since the error in the ground-state wavefunction enters linearly in all response properties. Thus, before starting escf or egrad, specify the keywords

$scfconv 7
$denconv 1d-7

in control, perform a dscf statistics run, if semi-direct integral processing is to be used (see Chapter 3.1), and (re-)run dscf or ridft,

dscf > dscf.out &

        or

ridft > ridft.out &

        in case of RI-J.

The above tight convergence criteria are also recommended for excited state geometry optimizations.