Atomic representation of the dispersion interaction energy

Abstract

A method is presented for dividing the intermolecular dispersion energy into intersite ‘atomic’ contributions. The dispersion energy and the multipole approximation to it are calculated for a series of atom (He,Ne,Ar)–linear molecule (N₂, CO, CO₂) systems. Damping functions which correct for the multipole approximation are found to be more isotropic for the ‘atomic’ components of the dispersion energy than for the total intermolecular dispersion energy, making the proposed method useful for modelling the dispersion energy. Applications of the method to larger molecules are considered.