Journal of Chemical Physics, Vol.105, No.20, 9316-9323, 1996
Polarizable Dipolar 2-Center Lennard-Jones Fluids - Computer-Simulations and Equation of State
Electrostatic contributions from permanent and induced dipoles have a considerable effect on the thermodynamic behavior of polar fluids. We derive a renormalized equation of state (1R-EOS) for the Helmholtz free energy of a polarizable dipolar two-center Lennard-Jones fluid, where for the first time polarizable dipolar interactions are combined with a nonspherical molecular shape. This hybrid EOS is constructed as a sum of the Helmholtz energy F-2CLJ for a two-center Lennard-Jones (2CLJ) fluid and a renormalized electrostatic contribution F-el. Wertheim’s renormalization procedure for inductive interactions was applied to a recently developed equation of state for dipolar 2CLJ fluids. We demonstrate that this renormalization applies to a simulation based equation of state and we determine the influence of the polarizability on the Helmholtz energy of a polarizable dipolar 2CLJ fluid as a function of its molecular elongation, Predictions from this renormalized equation of state for thermodynamic properties of the homogeneous phase show good agreement with molecular dynamics simulation data.
Keywords:THERMODYNAMIC PERTURBATION-THEORY;PHYSICALLY-BASED EQUATIONS;AUGMENTED BACK EQUATION;NONPOLAR LINEAR-MOLECULES;FREE-ENERGY;POLAR MIXTURES;CONSTRUCTION;STOCKMAYER;EQUILIBRIUM;DIATOMICS