A NEW METHOD FOR THE ESTIMATION OF INTERACTION ENERGIES IN LENNARD-JONES PURE LIQUIDS AND SOLUTIONS

A new theoretical model is proposed for the estimation of interaction energies in pure liquids as well as in dilute binary solutions, with particular emphasis on the London and Pauli contributions to the interaction energy. Basically, interaction energies are calculated as the sum of pair interactions between two molecules, with the average over all pair interactions being effected with the aid of a simplified pair distribution function. The method is tested on a large ensemble of pure liquids and dilute organic solutions. It is shown that this model, called PISA (pair interaction structureless approximation), is very efficient for liquids and solutions in which the intermolecular interactions are dominated by the London-Pauli contribution.