Phase Diagrams of Diatomic Molecules Using the Gibbs Ensemble Monte Carlo Method

Abstract

The Gibbs simulation method is used to explore the phase diagrams of a range of diatomic Lennard-Jones (DLJ) molecules. The dependence of the critical packing fractions on the bond-length of the molecules is examined. Reasonable agreement is found with both experimental and theoretical results. Particular attention is paid to the phase diagram of chlorine and the phase diagram is predicted for a more accurate anisotropic site-site potential. Good agreement is found with the experimental results for both the potential models. We conclude that for chlorine, the liquid-vapour phase envelope is not sensitive to the details of the potential model and therefore cannot be used to improve the model of the intermolecular forces.