Simple mixing rule for mixtures with exp-6 interactions

Monte Carlo simulations on mixture systems composed of hydrogen molecules and helium atoms have been performed to develop an improved one-fluid van der Waals model. This model is applicable to three-parameter potentials having an exponential-6 form. The proposed model has been shown to be as accurate as the conventional one-fluid van der Waals model, but it can be used over an extended density and temperature range, where the conventional model is physically less appropriate.