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.

ESP

The electrostatic potential method used in MOPAC is severely out-of-date.  The use of ESP is strongly discouraged.  A much faster and easier method is to use keyword `GRAPHF <graph.html>`__.

This is the ElectroStatic Potential calculation of K. M. Merz and B. H. Besler [31]. ESPcalculates the expectation values of the electrostatic potential of a molecule on a uniform distribution of points. The resultant ESP surface is then fitted to atom centered charges that best reproduce the distribution, in a least squares sense. To print out the ESP map, use POTWRT.