An empirical equation of state correlation is proposed for the Lennard-Jones model fluid. The equation in terms of the Helmholtz energy is based on a large molecular simulation data set and thermal virial coefficients. The underlying data set consists of directly simulated residual Helmholtz energy derivatives with respect to temperature and density in the canonical ensemble. Using these data introduces a new methodology for developing equations of state from molecular simulation. The correlation is valid for temperatures 0.5 < T/Tc < 7 and pressures up to p/pc = 500. Extensive comparisons to simulation data from the literature are made. The accuracy and extrapolation behavior are better than for existing equations of state.

Equation of State for the Lennard-Jones Fluid

Gibbs ensemble Monte Carlo simulations are reported for the vapor–liquid phase coexistence of argon, krypton, and xenon. The calculations employ accurate two-body potentials in addition to contributions from three-body dispersion interactions resulting from third-order triple-dipole, dipole–dipole–quadrupole, dipole–quadrupole–quadrupole, quadrupole–quadrupole–quadrupole, and fourth-order triple-dipole terms. It is shown that vapor–liquid equilibria are affected substantially by three-body interactions. The addition of three-body interactions results in good overall agreement of theory with experimental data. In particular, the subcritical liquid-phase densities are predicted accurately.

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Molecular simulation of the phase behavior of noble gases using accurate two-body and three-body intermolecular potentials

A new equation of state (EOS) is proposed for the Helmholtz energyF of the Lennard Jones fluid which represents the thermodynamic properties over a wide range of temperatures and densities. The EOS is written in the form of a generalized van der Waals equation.F =Fu +Fv. WhereFu is a hard body contribution andFA an anttractive dispersion force contribution. The expression forFH is closely related to the hybrid Barker Henderson pertubation theory. The construction ofFA is accomplished with the Setzmann Wagner optimization procedure on the basis of virial coefficients and critically assessed computer simulation data. A comparison with the EOS of Johnson et al. shows improvement in the description of the vapor liquid coexistence properties, thepvT data. and in peculiar, of the calorie properties. A comparison with the EOS of Kolafa and Nezbeda which appeared after the bulk of this work was finished shows still by about 30%.

An accurate Van der Waals-type equation of state for the Lennard-Jones fluid

Literature data on the thermophysical properties of the Lennard-Jones fluid, which were sampled with molecular dynamics and Monte Carlo simulations, were reviewed and assessed. The literature data ...

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Thermophysical Properties of the Lennard-Jones Fluid: Database and Data Assessment.

Perturbation theory based equation of state for polar molecular fluids: I. Pure fluids

An equation of state for lennard-jones pure fluids applicable over a very wide temperature range

An effective triplet potential for argon

Equation of state based on the weeks-chandler-andersen perturbation theory

Intermolecular potential for oxygen

Equation of state calculations and Monte Carlo simulations of internal energies, compressibility factors and vapor-liquid equilibria for Lennard-Jones fluid mixtures

Yoshimori Miyano

Papers

An equation of state for lennard-jones pure fluids applicable over a very wide temperature range

An effective triplet potential for argon

Equation of state based on the weeks-chandler-andersen perturbation theory

Intermolecular potential for oxygen

Equation of state calculations and Monte Carlo simulations of internal energies, compressibility factors and vapor-liquid equilibria for Lennard-Jones fluid mixtures