Atomic charge calculations for quantitative structure—property relationships

A previously published empirical charge scheme has been adapted for use in studies of quantitative structure‐property relationships. New parameters have been developed to allow the inclusion of nitrates, nitriles, sulfides, thiols, thiophenes, and sulfoxides. No changes have been made to the original scheme, thus preserving all previous results. A few simple additions to the program have made it possible to calculate atomic charges in a variety of ionic structures containing a formally positive nitrogen or a formally negative oxygen. The results obtained for ions are consistent with a number of concepts surrounding the familiar inductive and resonance effects.