Phase equilibria of Lennard-Jones dipolar plus quadrupolar fluids by Gibbs-ensemble Monte Carlo simulation

Gibbs simulation techniques have been used to calculate vapor-liquid equilibria of monatomic molecules having both dipoles and linear quadrupoles embedded in their Lennard-Jones cores. Results presented here include the coexistence curves and the estimates of the critical temperatures and densities for a range of values of both Q*2 and μ*2, where μ*2=μ²/({ε}σ³)=1.00 or 2.00 and Q*2=Q²/({ε}σ⁵)=1.00, 1.50, 2.00, or 2.50. Our simulation results indicate that both Tc* and ρc* increase with increasing values of the electrostatic moments, and both are more sensitive to Q*2 than μ*2.