中国物理B ›› 2000, Vol. 9 ›› Issue (12): 927-933.doi: 10.1088/1009-1963/9/12/009

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

ANALYTIC EQUATION OF STATE FOR GENERALIZED LENNARD-JONES SOLID INCLUDING LOWEST-ORDER ANHARMONIC AND CORRELATION CORRECTIONS

孙久勋1, 蔡灵仓2, 吴强2, 经福谦2   

  1. (1)Department of Applied Physics, University of Electronic Science and Technology, Chengdu 610054, China; (2)Laboratory for Shock Wave and Detonation Physics Research, Southwest Institute of Fluid Physics, Mianyang 730000, China
  • 收稿日期:2000-06-24 出版日期:2005-06-10 发布日期:2005-06-10
  • 基金资助:
    This work was supported by the Science Foundation outer of the China Academy of Engineering Physics under Grant No. 99010102.

ANALYTIC EQUATION OF STATE FOR GENERALIZED LENNARD-JONES SOLID INCLUDING LOWEST-ORDER ANHARMONIC AND CORRELATION CORRECTIONS

Sun Jiu-xun (孙久勋)a, Cai Ling-cang (蔡灵仓)b, Wu Qiang (吴强)b, Jing Fu-qian (经福谦)b   

  1. a Department of Applied Physics, University of Electronic Science and Technology, Chengdu 610054, China; b Laboratory for Shock Wave and Detonation Physics Research, Southwest Institute of Fluid Physics, Mianyang 730000, China
  • Received:2000-06-24 Online:2005-06-10 Published:2005-06-10
  • Supported by:
    This work was supported by the Science Foundation outer of the China Academy of Engineering Physics under Grant No. 99010102.

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摘要： Based on the cell model, the general formula for the free energy of solids is derived analytically with the lowest order anharmonic modification and correlation effect taken into account. Combining a method of summing over lattice sites, the analytic equation of state for generalized Lennard-Jones solid is derived. The calculations show that the agreement between theory and computer simulation is quite good and is significantly improved as compared with the numerical results in literature. The comparison of different effects shows the theory including all neighbors but only considering the lowest anharmonic and correlation effects may be a good and convenient approximation for practical solids. The approximation can be easily extended to the quantum case and other generalized potentials.

Abstract: Based on the cell model, the general formula for the free energy of solids is derived analytically with the lowest order anharmonic modification and correlation effect taken into account. Combining a method of summing over lattice sites, the analytic equation of state for generalized Lennard-Jones solid is derived. The calculations show that the agreement between theory and computer simulation is quite good and is significantly improved as compared with the numerical results in literature. The comparison of different effects shows the theory including all neighbors but only considering the lowest anharmonic and correlation effects may be a good and convenient approximation for practical solids. The approximation can be easily extended to the quantum case and other generalized potentials.

Key words: anharmonicity, correlation effect, equation of state, generalized Lennard-Jones system

中图分类号:  (General theory of equations of state and phase equilibria)

  • 64.10.+h
65.40.G- (Other thermodynamical quantities)