物理化学学报 >> 1993, Vol. 9 >> Issue (04): 438-441.doi: 10.3866/PKU.WHXB19930402

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熔融CaF2的径向分布函数

程兆年; 郏正明; 张静; 陈念贻   

  1. 中国科学院上海冶金研究所,中国科学院计算机化学开放实验室,上海 200050
  • 收稿日期:1993-02-20 修回日期:1993-03-22 发布日期:1993-08-15
  • 通讯作者: 程兆年

Radial Distribution Functions of Molten CaF2

Cheng Zhao-Nian; Jia Zheng-Ming; Zhang Jing; Chen Nian-Yi   

  1. Shanghai Institute of Metallargy, Academia Sinica, Laboratory of Computer Chemistry, Academia Sincia, Shanghai 200050
  • Received:1993-02-20 Revised:1993-03-22 Published:1993-08-15
  • Contact: Cheng Zhao-Nian

关键词: 径向分布函数, 熔融CaF2, 分子动力学模拟

Abstract: The coefficients b,ρ, and σ in Born-Mayer-Huggins potential were determined empirically for three interactions in CaF_2 system. The potential suggested in this work have reproduced the experimental lattice energy, bulk modulus, and three elastic constant very well. The radial distribution functions for molten calcium fluoride have been given by molecular dynamics simulation with the potential obtained. The results show that there is a great deal of difference in the three radial distribution functions. The first peak of radial distribution function is very sharp in the cation-anion case and smoothing down in the cation-cation and anion-anion case. The maximum of g_(--)(r) distribution is not high and a limp point appears between the first peak and the first valley of g_(--)(r) curve. The distances where the radial distribution function g_(+-)(r) has a maximum are 0.225 nm for T=2000 K and 0.221 nm for T=2200 K. These values are less than 0.2357 nm, the distance between cation and anion in crystalline phase of calcium fluoride, that indicates there are some "holes" and chain-like structures in molten system.

Key words: Radial distribution function, Molten CaF2, Molecular dynamics simulation