Thermodynamic properties of square-well fluids from a new coordination number model

Abstract

A new coordination number model is proposed for square-well fluids at λ = 1.5. The model modifies the theory previously developed for the coordination number of square-well fluids derived on the basis of the generalized Van der Waals theory by Largo and Solana. The present work proposes a new formula for the maximum reduced density and a new method to solve the integral corresponding to coordination number of hard sphere fluids. Thermodynamic quantities such as pair correlation function at contact, excess internal energy and constant volume excess heat capacity are determined employing the model. Good agreement is achieved between theoretical results and Monte Carlo (M.C.) data. As expected, the results of the excess heat capacity are poor at low temperatures.