Li_3Bi结构、力学和电子性质的第一性原理计算

A study on the First-principle calculations of the structural,Elastic and electronic properties of Li_3Bi:

基于密度泛函的线性响应理论,通过第一性原理的赝势方法,对Fm-3m相Li3Bi的结构、力学和电子性质做了系统的研究.优化得到的平衡结构参数与实验值符合得很好.计算表明,Fm-3m结构在零压下的焓最低,满足力学稳定标准,是最稳定的结构.计算得到的Fm-3m相Li3Bi的块体模量、剪切模量和弹性模量分别为30.2,25.5 GPa和59.6 GPa.德拜温度是312 K.Li3Bi具有小的弹性各向异性特征,是窄带隙的间接带隙半导体,带隙为0.45 eV.

The structural, elastic and electronic properties of Li3 Bi have been investigated by using first - principle pseudopotential method within the framework of density functional theory. The calculated equilibrium structural parameters agree well with the experiment. The enthalpy and elastic constants calculations show that Fm -3m structure is the most stable structure at zero pressure. For Li3Bi, the calculated bulk modulus, shear modu- lus, and the Youngg modulus are 30.2 GPa,25.5 GPa, and 59.6 GPa,respectively. When the Debye temperature is 312 K, Li3Bi has small elastic anisotropy. Li3Bi is an indirect semiconductor with narrow band gap （0.45 eV）.