THERMODYNAMICS OF SIMPLE FLUIDS FOLLOWING THE WEEKS-CHANDLER-ANDERSENPICTURE

In this work we propose some new analytic expressions that describe th e thermodynamics of simple fluids. These equations have a strong theor etical background (they are based on the Weeks-Chandler-Andersen pertu rbative theory), combine accuracy with simplicity and are valid over a wide range of temperatures and densities. Predictions of the thermody namics of the vapour-liquid equilibrium and molar heat capacity at a c onstant pressure for methane are made, giving good agreement with expe rimental results, and being compared with the predictions of the well known Soave equation.