布里渊区积分的外推方法
EXTRAPOLATION METHODS OF NUMERICAL QUADRATURE IN THE BRILLOUIN ZONE
涂梦凡1
作者信息
- 1. 北京师范大学数学科学学院,北京 100875
- 折叠
摘要
周期体系电子结构计算中的物理量需要通过在布里渊区上的能带积分得到.对于金属体系,被积函数在费米面穿过能带的地方出现间断,这导致一般数值积分方法的计算精度提升困难.本文基于smearing方法,分别通过一次和二次外推得到了关于展宽参数具有更高阶精度的数值格式.基于这类外推格式的数值方法在布里渊区k点离散相同的前提下给出了更高精度的布里渊区积分逼近,显著地提高了计算效率.我们通过对两类典型体系的数值模拟验证了这类外推方法的有效性.
Abstract
The physical quantities in the electronic structure calculation of periodic systems involve the band integral over the Brillouin zone.For metals,the integrand is discontinuous when the Fermi surface crosses through the energy band,which makes it difficult to improve the calculation accuracy of general numerical integration methods.Based on smearing methods,we propose two numerical formats with higher order precision about the broadening param-eters by first and second extrapolation respectively.The numerical method based on this kind of extrapolation scheme gives more precise integral approximation over the Brillouin zone with the premise of the same discrete k-point in Brillouin region,and significantly im-proves the computational efficiency.The efficiency of the extrapolation methods is verified by numerical tests on two typical systems.
关键词
周期体系/能带结构/布里渊区/smearing方法/外推方法Key words
Periodic systems/Band structure/Brillouin zone/Smearing methods/Ex-trapolation methods引用本文复制引用
基金项目
国家重点基础研发计划(2019YFA0709600)
国家重点基础研发计划(2019YFA0709601)
出版年
2024
NETL
NSTL
万方数据