高压下固态Kr弹性性质、电子结构和光学性质的第一性原理计算

采用密度泛函理论中平面波基矢,模守恒赝势结合局域密度近似以及广义梯度近似对固态Kr在高压下的结构以及弹性性质进行了研究, 通过计算发现弹性常数，Debye温度以及声速都随压力的增大而增大,所计算的弹性常数与实验和其他的理论符合的很好. 利用Debye模型得到了固态Kr的热力学性质, 熵随压力的增大而减小，随温度升高而升高；而定容热容C_v,定压热容C_p则随温度升高而升高，而且C_v在达到一定温度时趋于定值，所得的热力学性质和实验值是相符的．最后还预测了固态Kr在高压下的电子结构和光学性质, 计算结果表明随压力的增加固态Kr的前沿能带变窄，光吸收系数增大，吸收峰增宽，电子更容易发生跃迁，固态Kr有可能转化为半导体．关键词：Kr第一性原理弹性常数光学性质

Elastic constants, electronic structure and optical properties of solid krypton under pressure by first-principles calculations

The elastic constants, electronic structure and optical properties of solid krypton are investigated by first-principles plane-wave pseudo-potential method in the scheme of density functional theory within local density approximation and generalized gradient approximation. The calculated elastic constants under pressure are in good agreement with the experimental and theoretical data. The obtained Debye temperature and sound velocity increase with pressure. The electronic structure and optical properties under pressure are also predicted, the energy band gap decreases, optical absorption coefficient increases and absorption peak widens under pressure. This leads to easy electron transition and solid krypton probably becomes semiconductor.