If this keyword is set to ON (=1), then the QRHF orbitals specified by the CFOUR_QRHF_GENERAL CFOUR_QRHF_ORBITAL and CFOUR_QRHF_SPIN (nyi?) keywords are used as a starting guess for a restarted SCF procedure. This can be an extremely useful way to converge “difficult” SCF solutions, such as those that correspond to states that are not the lowest states of a given symmetry. Note that when this option is used, the calculation that is performed is not a QRHF-CC calculation; it is instead a UHF-based or ROHF-based calculation, depending on what type of reference is specified by the CFOUR_REFERENCE keyword. The QRHF aspect of the calculation is used simply as a device to converge the orbitals.
- Type: boolean
- Default: false
