ACCURATE ANALYTICAL REPRESENTATIONS OF THE CORE-ELECTRON DENSITIES OFTHE ELEMENTS 3 THROUGH 118

The core-electron density in a molecule is defined as a sum of perfect ly transferable, spherically symmetrical atomic contributions rho(AC)( Z,N,r). Analytical functions can be fitted to rho(AC)(Z,N,r) with a ch arge-conserving algorithm. The relativistic core-electron densities of the elements 3 through 118, obtained from numerical multiconfiguratio nal Dirac-Fock calculations, are accurately represented by linear comb inations of 50 s-type Gaussian primitives arranged in even-tempered ba sis sets. These representations are well suited for the augmentation o f valence-electron densities produced by semiempirical methods and app roaches involving effective core potentials. Calculations of the elect ronic properties of atoms in the TiCl4 and CdH2 molecules that employ such augmentation are presented. (C) 1997 American Institute of Physic s.