REFERENCE HYPERNETTED-CHAIN THEORY FOR LINEAR MOLECULAR FLUIDS - A COMPREHENSIVE STUDY OF THE GAS-LIQUID COEXISTENCE

We have used the reference hypernetted chain theory (RHNC) with a hard -core reference fluid treated in the modified Verlet's approximation ( VM) to obtain the gas-liquid coexistence curve of centrosymmetric line ar molecular fluids modeled via site-site Lennard-Jones interactions w ith and without electrostatic forces. Explicit results are presented f or the gas-liquid equilibrium of molecular nitrogen and carbon dioxide . Thermodynamic consistency constraints are crucial to define the refe rence system. Comparison with Gibbs Ensemble Monte Carlo and density f unctional theory (DFT) calculations evidence the RHNC-VM theory is an excellent tool for predicting coexistence densities and vapor pressure s of linear molecular fluids. (C) 1996 American Institute of Physics.