BaMgF_4晶体电子结构及光学性质的第一性原理研究

First Principle Study on the Electronic Structures and Absorption Spectra of the BaMgF_4 Crystal

运用CASTEP软件计算了完整的BaMgF4晶体的电子结构、介电函数和吸收光谱。采用剪刀算子进行修正,根据实验结果和计算结果比对,确定剪刀算子值为4.77 eV。计算结果显示完整的BaMgF4晶体在14.203-14.475eV和21.480-21.767 eV两个区间有很明显的吸收峰,吸收边为10.337 eV,对应BaMgF4晶体的本征吸收边125nm,计算结果与实验结果基本一致。

The electronic structures and absorption spectra for the perfect BaMgF4 crystal have been calculated using density functional theory code CASTEP with the lattice structure optimized.The calculated spectra of the BaMgF4 crystal exhibit two absorption bands located at 14.2-14.475 eV and 21.48-21.767 eV.The minimal absorption edge is 10.337 eV,which is so close to the intrinsic absorption edge 10.333 eV（125 nm）.