基于能带结构的布里渊区非均匀四面体网格生成技术

A Band Structure Based Nonuniform Brillouin Zone Tetrahedron Approach

基于非局域赝势能带计算及四面体网格单元中能量满足线性关系,提出一种布里渊区非均匀四面体网格产生方法,在满足精度条件下能自动得出数目最少的四面体网格,使布里渊区积分计算的精度和效率大为提高.通过对硅、锗两种金刚石结构半导体简约布里渊区所产生网格的比较,表明该方法可以根据能带结构的特点自动生成优化的非均匀网格.对现有的态密度四面体计算公式进行了补充完善,并根据生成的网格和完善后的公式计算了硅和锗导带第一、二能带的态密度.

We propose a ＂state of art ＂tetrahedron sampling scheme based on a nonlocal pseudopotential bandstmcture calculation and linear energy interpolation in each tetrahedron cell. In this approach, a relatively small amount of tetrahedrons are produced automatically and the Brillouin integration is calculated with higher precision and efficiency. In an application to diamond materials of Si and Ge, optimized nonuniform meshes are obtained automatically in the 1/48 irreducible wedge of the brillouin zone. A complement is given for the integrality of the present tetrahedron DOS expression and the DOS＇s for the first and second conductance band of Si and Ge are obtained with this grid and the supplemented expression.