PHASE-DIAGRAMS OF DIATOMIC-MOLECULES USING THE GIBBS ENSEMBLE MONTE-CARLO METHOD

The Gibbs simulation method is used to explore the phase diagrams of a range of diatomic Lennard-Jones (DLJ) molecules. The dependence of th e critical packing fractions on the bond-length of the molecules is ex amined. Reasonable agreement is found with both experimental and theor etical results. Particular attention is paid to the phase diagram of c hlorine and the phase diagram is predicted for a more accurate anisotr opic site-site potential. Good agreement is found with the experimenta l 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.