The Parametric Molecular Electrostatic Potential of Wang and Ford [45,46] is generated. This method is very accurate, but has only been parameterized for H, C, N, O, F, P, S, Cl, and Br, and only for the AM1 method. By default, the plane used is the X-Y plane at Z=0. Use PMEPR for other planes. Other keywords, e.g., MINMEP (to print the minima) or PRTMEP (to write data for esplot to use) must be present.