Intermolecular Forces in the Region of Small Orbital Overlap

Abstract

The perturbation method of Yaris for the case where the unperturbed wavefunction is not an eigenfunction of the unperturbed Hamiltonian is developed to give an expression for intermolecular energies in the region of small orbital overlap. The resulting expressions are the same as these obtained earlier using a more traditional aproach, but the derivation does not suffer the lack or rigor in this earlier treatment.