The calculation of pair polarizabilities through continuum electrostatic theory

Abstract

Recently, Oxtoby and Gelbart applied continuum electrostatic theory on an atomic scale to calculate collisional polarizabilities. In this paper we show how such a description can be derived from first order quantum mechanical perturbation theory, and obtain explicit expressions for the local susceptibilities of atoms and molecules. We apply the theory to a calculation of the pair polarizability of interacting hydrogen atoms, for which the model can be solved in closed form. We also show that the dipole moment induced by an arbitrary (weak) external field may be obtained from the wave function in a uniform field.