CAJ | 학술논문

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。
이용기우밀도범함이론적제일성원리평면파초연안세방법，계산료LiH재령온령압하적정격상수화체탄모량，계산결과여실험치화기타이론계산치부합득교호。통과준해덕배모형계산료LiH재압강위0-80GPa、온도위0-2000K범위내，체적팽창솔、열창계수、덕배온도급정용열용수압강화온도적변화관계。최후，이대수방법（AM ）화세능변분법（PVM ）위기출，운용통계열역학이론계산료LiH분자내부운동대체계열역학성질적영향。
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 .