Conformational dependence of molecular surface electrostatic potentials

In a series of earlier studies, we showed that a variety of solution, liquid, and solid-phase properties can be represented analytically in terms of quantities related to the electrostatic potentials on molecular surfaces. These quantities include the positive and negative extrema, the positive and negative average values and variances, and the average deviation. We have now investigated how sensitive these quantities are to the molecular conformation. Surface potentials were computed at the HF/6-31G* level for a total of 35 conformations of 10 different molecules. Our overall conclusion is that conformational effects upon applications of molecular surface electrostatic potentials are most likely to be of concern if (a) formation of the conformer considerably diminishes the internal polarity and/or (b) the application in question is strongly dependent upon the positive variance. (C) 1999 John Wiley & Sons, Inc.