Two-body intermolecular potentials from second virial coefficient properties.

Area of Science:

• Physical Chemistry
• Computational Chemistry
• Thermodynamics

Background:

• Accurate intermolecular potentials are crucial for understanding fluid behavior.
• Existing potentials often require complex calculations or lack general applicability.
• Second virial coefficients offer a route to simplified potential models.

Purpose of the Study:

• To develop a straightforward method for deriving two-body intermolecular potentials for noble gases.
• To incorporate three-body interactions for a more complete fluid description.
• To validate the derived potentials against experimental data and simulations.

Main Methods:

• Transformation of generic n-m Lennard-Jones/Mie potentials using second virial coefficient data.
• Development of a density-dependent term to account for three-body interactions.
• Molecular simulations of vapor-liquid equilibria using the new potentials.

Main Results:

• The derived two-body potentials for Ne, Ar, Kr, and Xe show good agreement with accurate ab initio calculations.
• The combined two- and three-body potentials accurately predict vapor-liquid equilibria for noble gases.
• The 10-8 Lennard-Jones/Mie potential combined with the three-body term is identified as a suitable model for noble gases.

Conclusions:

• The proposed method effectively yields simplified yet accurate intermolecular potentials.
• The inclusion of three-body interactions is essential for describing real fluid behavior.
• The developed potentials provide a robust framework for simulating noble gas systems.