EXTRACTION OF STEWART ATOMS FROM ELECTRON-DENSITIES

Stewart atoms are the unique nuclear-centered spherical functions whos e sum best fits a molecular electron density in a least-squares sense. It is difficult, however, to express Stewart atoms in closed form. We therefore introduce new closed-form approximations, Stewart-Slater at oms, and show that these can be found efficiently from molecular multi pole moments. Using examples, we argue that the parameters of Stewart- Slater atoms can yield insight into the nature of chemical bonding.