A graphical representation of the electrostatic potential and electric field on a molecular surface

The graphics program presented, ARCHEM, draws the molecular electrostatic potential (MEP) on a molecular surface color-coded according to the magnitude of the potential. Vectors can be drawn on the surface to show the electric field surrounding the molecule and color-coded according to the magnitude of the field. The electrostatic potential (ESP) calculated from the wave function or from net atomic charges using GAUSSIAN 80 UCSF1,2 can be plotted at points on a shell surrounding the molecule. For the neurotransmitter glycine zwitterion, the MEP is calculated from the wave function and from different point charge models, and the results are represented graphically.