高压下LiF结构稳定性和力学性质的第一性原理研究  

First Principles Studies of The Structural and Mechanical Stability of LiF Crystal

作　　者：王秀芳 黄多辉[1] WANG Xiufang;HUANG Duohui(Computational Physics Key Laboratory of Sichuan Province,Yibin University,Yibin,Sichuan 644000,China;School of Physical Science and Technology,Southwest Jiaotong University,Chengdu,Sichuan 610031,China)

机构地区：[1]宜宾学院计算物理四川省高校重点实验室,四川宜宾644000 [2]西南交通大学物理科学与技术学院,四川成都610031

出　　处：《宜宾学院学报》2021年第6期57-61,共5页Journal of Yibin University

基　　金：计算物理四川省高校重点实验室开放基金项目(JSWL2014KF01;2020JSWLZD003)。

摘　　要：使用第一性原理方法比较分析压强从0到700 GPa范围LiF晶体B1相(NaCl结构)和B2相(CsCl结构)的结构稳定性和力学性质.结果发现:常压下LiF稳定结构为NaCl结构的B1相,采用GGA方法计算的晶格常数、弹性常数和体弹模量与实验数据符合很好.在此基础上采用同样的方法得到了压强在0到700 GPa下LiF的B1相和B2相晶格常数、能隙、弹性常数、体弹模量、剪切模量、杨氏模量和德拜温度随压强的变化关系.The structural and mechanical stability are studied comparatively by using the first⁃principles calculations up to pressure of 700 GPa in which the LiF crystals are in B1 phase(NaCl structure)and B2 phase(CsCl structure).The results show that B1 phase of LiF crystal is stable under ambient pressure,and the structural parameters,elastic constant and bulk modulus are in good agreement with experimental measurements by use of GGA method.On the base of the same method,the structural parameters,energy gap,elastic constant,shear modulus,bulk modulus and Young􀆳s modulus and Debye temperature under different pressures are successfully obtained.

关 键 词：第一性原理 力学性质 LIF 

分 类 号：O641[理学—物理化学] O649[理学—化学]