MULTICENTRIC CHARGES FOR THE ACCURATE REPRESENTATION OF ELECTROSTATIC INTERACTIONS IN FORCE-FIELD CALCULATIONS FOR SMALL MOLECULES

A strategy to define multicentric electrostatic char es is presented. It is based on the placement of potential-derived charges at the atomic nuclei, but also at other clearly defined positions. In general, extra charges are located near the nuclei, and often along chemical bonds, which facilitate their implementation in force fields. The use of multicentric charges notably improves the ability of Coulombic molecular electrostatic potentials (MEPs) to reproduce quantum mechanical values. The strategy seems especially useful for the classical study of condensed phases and in general for the electrostatic representation of any small, rigid molecule.