Note

This website is presently under development. The primary website for MOPAC is still http://openmopac.net until the majority of its contents have been migrated here.

NOANCI

Use numerical derivatives for configuration interaction calculations and corrections (e.g. open-shell RHF) instead of Liotard’s analytical method [6], which is the default method. Numerical derivatives are much slower and should only be used to check the analytical derivatives if there are concerns about their validity or accuracy.