<i>Ab initio</i>valence bond calculation of intermolecular forces using a non-orthogonal basis set: HeHe and HeLi systems

Abstract

A variational valence bond method of calculating intermolecular forces is presented. Its main feature is the use of a non-orthogonal basis set in order to avoid overextension basis errors. Test calculations of the dispersion energy in HeHe and HeLi systems are shown.