Mg2Si弹性性质及热力学性质的第一性原理计算

采用基于第一性原理的赝势平面波方法系统地计算了Mg2Si弹性性质和热力学性质.根据计算数据得出Mg2Si在不同压强下的弹性常数,得出相对晶格常数(α/α0)、相对体积(V/V0)、体弹性模量与压强和温度的关系.通过准谐德拜模型计算了Mg2Si的热力学性质,如比热容和德拜温度,计算出的德拜温度与实验值基本相同.

First-principles Calculations of Elastic and Thermodynamic Properties of Mg2Si

The elastic constants and some thermodynamic properties of Mg2 Si are calculated systematically by usingthe first-principles pseudopotential plane wave method.The elastic constants of Mg2Si under different pressures are calculated.The dependences of the relative lattice parameters α/α0 on pressure P,the relative primitive volume V/V0 on pressure P,as well as the bulk modulus B with temperature and pressure are obtained successfully.The heat capacities and the Debye temperatures are calculated through quasi-harmonic Debye model.The calculated Debye temperature is equal to the experimental data.