Inferring transferable intermolecular potential models

Abstract

Discontinuous molecular dynamics is combined with thermodynamic perturbation theory to provide an efficient basis for characterising molecular interactions based on vapour pressure and liquid density data. Several prospective potential models are discretised to permit treatment by Barker–Henderson perturbation theory. The potentials are characterised by 11 wells ranging over radial distances from the site diameter to three times that diameter. Considered potential models include the Lennard-Jones (LJ), square-well, Yukawa (Yuk) and multi-line potentials, and their combinations. The optimal model is found to be a combination of square-well and Yuk potentials, with the switch position and Yuk decay set to universal values. This model provides average vapour pressure deviations of less than 10% for a database of 86 aliphatic, aromatic and naphthenic compounds. The LJ potential provides the least competitive accuracy. Considering statistical information criteria facilitates the identification of the optimal model.