International Journal of Thermophysics

, Volume 10, Issue 2, pp 447–457 | Cite as

Exact calculations of fluid-phase equilibria by Monte Carlo simulation in a new statistical ensemble

  • A. Z. Panagiotopoulos


A recently proposed method, Monte Carlo simulation in the Gibbs ensemble, allows the prediction of phase equilibria from knowledge of the intermolecular forces. A single computer experiment is required per coexistence point for a system with an arbitrary number of components. The new technique has significant advantages relative to free-energy methods that have been used for phase equilibrium calculations is the past. In this work, a variation of the Gibbs method appropriate for calculations in mixtures with large differences in molecular size is developed. The method is applied for the calculation of high-pressure phase equilibria in two mixtures of simple monatomic fluids, the systems argon-krypton and neon-xenon. Pairwise additive potential functions of the Lennard-Jones type are used to describe the intermolecular interactions. Agreement with experimental results is generally good over a wide range of temperatures and pressures, including the fluid-fluid immiscibility region for the neon-xenon system. Results from the Van der Waals one-fluid theory are compared with experimental data and computer simulation predictions. Agreement is excellent for the mixture with small differences in size (argon-krypton), but the theory fails to describe the coexistence curve for the highly asymmetric system neon-xenon.

Key words

computer simulation intermolecular potential functions Lennard-Jones Monte Carlo phase equilibria vapor-liquid equilibria 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    M. P. Allen and D. J. Tildesley,Computer Simulation of Liquids (Clarendon Press, Oxford, 1987).Google Scholar
  2. 2.
    D. Frenkel, inMolecular Dynamics Simulation of Statistical Mechanical Systems, Proceedings of the International School of Physics “Enrico Fermi,” course 97, G. Cicotti and W. G. Hoover, eds. (North-Holland, Amsterdam, 1986), pp. 151–183.Google Scholar
  3. 3.
    A. Z. Panagiotopoulos, U. W. Suter, and R. C. Reid,Ind. Eng. Chem. Fund. 25:525 (1986).Google Scholar
  4. 4.
    D. Fincham, N. Quirke, and D. J. Tildesley,J. Chem. Phys. 84:4535 (1986).Google Scholar
  5. 5.
    B. Widom,J. Chem. Phys. 39:2808 (1963).Google Scholar
  6. 6.
    A. Z. Panagiotopoulos,Mol. Phys. 61:813 (1987).Google Scholar
  7. 7.
    A. Z. Panagiotopoulos, N. Quirke, M. Stapleton, and D. Tildesley,Mol. Phys. 63:527 (1988).Google Scholar
  8. 8.
    A. Z. Panagiotopoulos,Mol. Phys. 62:701 (1987).Google Scholar
  9. 9.
    M. S. Stapleton, D. J. Tildesley, N. Quirke, and A. Z. Panagiotopoulos,Mol. Simulat. 2:147 (1989).Google Scholar
  10. 10.
    D. A. Kofke and E. D. Glandt,J. Chem. Phys. 87:4881 (1987).Google Scholar
  11. 11.
    G. C. Maitland, M. Rigby, E. B. Smith, and W. A. Wakeham,Intermolecular Forces (Clarendon Press, Oxford, 1981).Google Scholar
  12. 12.
    J. A. Barker, R. A. Fisher, and R. O. Watts,Mol. Phys. 21:657 (1971).Google Scholar
  13. 13.
    J. J. Nicolas, K. E. Gubbins, W. B. Street, and D. J. Tildesley,Mol. Phys. 37:1429 (1979).Google Scholar
  14. 14.
    Y. Adachi, I. Fijihara, M. Takamiya, and K. Nakanishi,Fluid Phase Equil. 39:1 (1988).Google Scholar
  15. 15.
    J. O. Hirschfelder, C. F. Curtiss, and R. B. Bird,Molecular Theory of Gases and Liquids (John Wiley, New York, 1954).Google Scholar
  16. 16.
    K. P. Shukla,Mol. Phys. 62:1143 (1987).Google Scholar
  17. 17.
    C. G. Gray and K. E. Gubbins,Theory of Molecular Fluids (Clarendon Press, Oxford, 1984).Google Scholar
  18. 18.
    A. Deerenberg, J. A. Schouten, and N. J. Trappeniers,Physica 101A:459 (1980).Google Scholar
  19. 19.
    C. Hoheisel,Mol. Phys. 62:385 (1987).Google Scholar
  20. 20.
    J. A. Schouten, A. Deerenberg, and N. J. Trappeniers,Physica 81A:151 (1975).Google Scholar
  21. 21.
    A. L. Gosman, R. D. McCarty, and J. G. Hust,Thermodynamic Properties of Argon from the Triple Point to 300 K at Pressures to 1000 Atmospheres (Natl. Stand. Ref. Data Ser., U.S. Natl. Bur. Stand, 1969).Google Scholar
  22. 22.
    K. S. Shing and K. E. Gubbins,Mol. Phys. 49:1121 (1983).Google Scholar
  23. 23.
    K. P. Shukla and J. M. Haile,Mol. Phys. 62:617 (1987).Google Scholar
  24. 24.
    L. C. Van den Bergh, J. A. Schouten, and N. J. Trappeniers,Physica 132A:537 (1985).Google Scholar

Copyright information

© Plenum Publishing Corporation 1989

Authors and Affiliations

  • A. Z. Panagiotopoulos
    • 1
  1. 1.School of Chemical EngineeringCornell UniversityIthacaUSA

Personalised recommendations