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.

MOPAC

The keyword MOPAC is provided in order to allow compatibility with earlier versions of MOPAC which did not require the connectivity of the second or third atoms to be explicitly defined. In general, MOPAC should be used for data sets constructed using an editor; data sets generated by GUIs normally give the connectivities of atoms 2 and 3.