Use of some predominant intermolecular (or interatomic) energy contributions to characterize van der waals molecules. Ab initio calculations on two neon atoms

Abstract

In previous papers, we presented an evaluation of the dispersion energy, using a double perturbation scheme and an “Epstein-Nesbet partition” of the individual molecular hamiltonians. The purpose of the present work is to check whether such dispersion energies, added to the SCF supermolecule energies, are able to give a reasonable description of the intermolecular (or interatomic) interactions. In order to compare our values with experimental data or with other ab initio and and semi-empirical work, we have studied the Ne + Ne system. The depth of the van der Waals minimum obtained is about 71% of the value derived from experimental data.