# CFOUR_HFSTABILITY

> Control analysis of the stability of RHF, ROHF and UHF wavefunctions, as well as a possible search for a lower SCF solution. There are three possible options for this keyword. OFF (=0) does nothing, while ON (=1) performs a stability analysis and returns the number of negative eigenvalues in the orbital rotation Hessian. A third option, FOLLOW (=2) performs the stability analysis and then proceeds to rotate the SCF orbitals in the direction of a particular negative eigenvalue of the orbital rotation Hessian (see the explanation of keyword CFOUR_ROT_EVEC , after which the SCF is rerun.

> - Type: string
> - Possible Values: OFF, ON, FOLLOW
> - Default: OFF