1.1.1 electrostatic description of molecular systems

Abstract

We propose a new simplified description of the molecular electronic density in terms of atomic contributions represented by their charges, dipoles, quadrupoles, etc. The partition of the electronic density is performed resulting in : (i) Multipolar moments of the molecule are reproduced. (ii) The atomic contributions are as close as possible to spherical charge distributions. The Mulliken partition is the simplest particular case in which dipoles, quadrupoles, etc. are neglected. The results show similar descriptions for chemically similar atoms in different molecules (calculated with the same basis) as well as a remarkable sensitivity of the electronic density versus changes in the basis set.