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.

RECALC

RECALC=n calculates the Hessian every n steps in the EF optimization. For small n this is costly but is also very effective in terms of convergence. RECALC=10 and DMAX=0.10 can be useful for difficult cases. In extreme cases RECALC=1 and DMAX=0.05 will always find a stationary point, if it exists.