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.

TS

Within the Eigenvector Following routine [7], the option exists to optimize a transition state. To do this, use TS. Preliminary indications are that the TS method is much faster and more reliable than either `SIGMA <sigma.html>`__ or `NLLSQ <nllsq.html>`__. TS appears to work well with Cartesian coordinates. In the event that TSdoes not converge on a stationary point, try adding `RECALC=5 <recalc.html>`__ to the keyword line.

Caution: When a transition state is optimized, and some optimization flags are not set for optimization, the optimized structure might have a significant gradient.  This usually happens when the fixed atoms are not in their optimized positions.