LIQUID-VAPOR COEXISTENCE OF THE GAY-BERNE FLUID BY GIBBS-ENSEMBLE SIMULATION

The Gibbs-ensemble Monte Carlo simulation method is used to predict the liquid-vapour coexistence of a fluid whose molecules interact with a cut and shifted Gay-Berne pair potential with elongation k = 3 and well-depth ratio k' = 5. From these simulation results we estimate the temperature, density and pressure at the critical point to be kT(c)/epsilon-o = 0.489 +/- 0.005, rho-c-sigma-o3 = 0.096 +/- 0.004, p(c)sigma-o3/epsilon-o = 0.0138 +/- 0.0014. We also present evidence of the existence of the vapour-isotropic-liquid-solid triple point. Comparison with the density-functional approximation shows that this theoretical method predicts coexistence and critical temperatures that are too low.