LiH的热力学性质及分子内部运动对体系热力学性质的影响  

Thermodynamic properties of LiH and the effect of internal motion of LiH molecules on the thermodynamic properties of system

作　　者：黎波[1] 任维义[1] 

机构地区：[1]西华师范大学理论物理研究所,南充637002

出　　处：《原子与分子物理学报》2014年第5期795-801,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10474068);四川省科技厅资助项目(009JY0143)

摘　　要：利用基于密度泛函理论的第一性原理平面波超软赝势方法,计算了LiH在零温零压下的晶格常数和体弹模量,计算结果与实验值和其他理论计算值符合得较好.通过准谐德拜模型计算了LiH在压强为0-80GPa、温度为0-2000K范围内,体积膨胀率、热涨系数、德拜温度及定容热容随压强和温度的变化关系.最后,以代数方法(AM)和势能变分法(PVM)为基础,运用统计热力学理论计算了LiH分子内部运动对体系热力学性质的影响.The lattice constant and bulk modulus of LiH at zero temperature （T=0K） and zero pressure （P= 0GPa） were calculated by the first-principle plane-wave density function theory pseudopotential method .The calculated results are in good agreement with the experimental values and the other theo-retical ones .Through the quasi-Debye model ,we successfully obtained the thermodynamic properties of LiH ,such as volume expansion ratio ,thermal expansion coefficient ,Debye temperature and the heat ca-pacity in the temperature range from 0 to 2000K and pressure range from 0 to 80GPa .Finally ,based on the algebraic method（AM ） and potential energy variational method （PVM ） ,the effect of internal motion of LiH molecules on the thermodynamic properties of system was calculated by the statistical thermody-namic theory .

关 键 词：LIH 第一性原理 统计热力学理论 热力学性质 

分 类 号：O551.3[理学—热学与物质分子运动论]