局域从头计算方法在周期性体系中计算光学能隙。二、固体周期性密度拟合局域组态相互作用单激发方法。

Local ab initio methods for calculating optical bandgaps in periodic systems. II. Periodic density fitted local configuration interaction singles method for solids.

机构信息

Institute for Physical and Theoretical Chemistry, Universität Regensburg, Universitätsstrasse 31, D-93040 Regensburg, Germany.

出版信息

J Chem Phys. 2012 Nov 28;137(20):204119. doi: 10.1063/1.4767775.

DOI:10.1063/1.4767775

PMID:23205993

Abstract

We present a density fitted local configuration interaction singles (CIS) method for calculating optical bandgaps in 3D-periodic systems. We employ an Ewald technique to carry out infinite lattice summations for the exciton-exciton interaction, and robust product-density specific local density fitting in direct space for the electron-hole interaction. Moreover, we propose an alternative to the usual cyclic model with Born-von Karman periodic boundary conditions, the so called Wigner-Seitz supercell truncated infinite model, which exhibits much improved convergence of the CIS excitation energy with respect to the size of the supercell. Test calculations on a series of prototypical systems demonstrate that the method at the present stage can be used to calculate the excitonic bandgaps of 3D periodic systems with up to a dozen atoms in the unit cell, ranging from wide-gap insulators to semiconductors.

摘要

我们提出了一种用于计算三维周期性系统光学带隙的密度拟合局域组态相互作用单激发（CIS）方法。我们采用 Ewald 技术对激子-激子相互作用进行无限晶格求和，并在直接空间中对电子-空穴相互作用进行鲁棒的乘积密度特定局部密度拟合。此外，我们提出了一种替代通常的具有 Born-von Karman 周期性边界条件的循环模型的方法，即所谓的 Wigner-Seitz 超胞截断无限模型，该模型在超胞大小方面表现出 CIS 激发能更好的收敛性。对一系列原型系统的测试计算表明，在现阶段，该方法可用于计算具有多达十几个原子的单元的三维周期性系统的激子带隙，范围从宽能隙绝缘体到半导体。