New equation of state for double Yukawa potential with application to Lennard–Jones fluids

Abstract

We present a simple but accurate equation of state for double Yukawa fluids based on the variational series mean spherical approximation (VSMSA). This allows us to investigate the vapour–liquid equilibrium and its related thermodynamic properties. The comparisons with computer simulation results of the Lennard–Jones (LJ) potential suggest the importance of treating the attractive tail of the potential accurately via VSMSA. The estimated reduced critical parameters T _C = 1.342, ρ _C = 0.29 and P _C = 0.135 are in good agreement with other theoretical and computer simulation results for the LJ system.

Keywords:

• theory of simple liquids
• equation of state of simple liquids
• properties of double Yukawa potential
• liquid–vapour coexistence

Acknowledgements

We are grateful to the Sultan Qaboos University for the research project # IG/Sci/Phys/07/04 and its substantial financial support for completing this work.