Computation and Interpretation of Electron Distributions in Inorganic Molecules

Abstract

Although the electron density has always been a useful way of characterizing the electronic structure of a molecule, it attains special significance with the theorem of Hohenberg and Kohn1, which provides a direct link between the electron density and the energy of the system.2 The total electron density of a molecular system, like the total energy, differs little from that of its constituent atoms. Of course, it is just the small differences between the atomic density (energy) and the molecular density (energy) which are responsible for the chemical bond. Because of our interest in the chemical bond, we usually find the deformation density more useful than the total density. The deformation density, which is the total molecular density minus the density of spherical, ground-state atoms, can be interpreted as the changes in electron density which occur upon forming the molecule from its atoms.