A measure of protein-protein interactions known as the osmotic second

virial coefficient, or [B.

w], and second

virial coefficient which is a quantification of the polymer-solvent interaction for polymer chains, [A.

We employ state-of-the-art pair and three-body potentials with path-integral Monte Carlo (PIMC) methods to calculate the third density

virial coefficient C(T) for helium.

The equation contains

virial coefficients up to the third

virial coefficient.

But, it represents poorly the supercritical state: the properties of the fluids in this region are inaccurately predicted, in particular, derived properties such as the second

virial coefficient [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] and the Joule-Thomson inversion curve.

Two tested submodels, which closely resemble the real gas model, were based on substitution of the

virial coefficient contribution to property values in favor of a simple correlation.

Intermolecular Potentials and the Evaluation of the Second

Virial Coefficient.

Knowledge of the pair and three-body potential-energy surfaces of helium is now sufficient to allow calculation of the third density

virial coefficient, C(T), with significantly smaller uncertainty than that work, we employ the best available pair and three-body potentials for helium and calculate C(T) with path-integral Monte Carlo (PIMC) calculations supplemented by semiclassical calculations.

For Lennard-Jones gases, temperature dependence of the dimensionless second

virial coefficient B * (i.

He further quantified this solubility and its limits by using static light scattering to measure a parameter called the second

virial coefficient B.

No attempts were made to determine the

virial coefficients theoretically, although experimental values of the second

virial coefficient were used in the development of the formulation in Ref.

It is notable that for pure component the chemical contribution to the second

virial coefficient should converge to the following limit (Prausnitz et al.