Statistical mechanics of interacting dipoles

Abstract

The electrostatic energy of a system of molecules with permanent and induced dipole moments is calculated as a power series in the polarizabilities. The successive terms of the series refer to interactions of 2, 3, 4,... molecules. The first and second moments of the electrostatic energy are calculated to the first order in the polarizability, and used to give approximate expressions for the contribution of electrostatic forces to the free energy of polar liquids and solutions. The results are compared with corresponding results calculated to zero order in polarizability by Pople. The semi-macroscopic approach of Martin and of Bonnor is examined, and shown to contain inconsistencies, which are removed by a slightly different approach.