Accurate analytical representations of the core-electron densities of the elements 3 through 118

The core-electron density in a molecule is defined as a sum of perfectly transferable, spherically symmetrical atomic contributions ρ_AC(Z,N,r). Analytical functions can be fitted to ρ_AC(Z,N,r) with a charge-conserving algorithm. The relativistic core-electron densities of the elements 3 through 118, obtained from numerical multiconfigurational Dirac-Fock calculations, are accurately represented by linear combinations of 50 s-type Gaussian primitives arranged in even-tempered basis sets. These representations are well suited for the augmentation of valence-electron densities produced by semiempirical methods and approaches involving effective core potentials. Calculations of the electronic properties of atoms in the TiCl₄ and CdH₂ molecules that employ such augmentation are presented.