New methods for electronic excited states of solids using localized basis

使用局域基研究固体电子激发态的新方法

基本信息

批准号：
14540368
负责人：
KATAGIRI Hideki
金额：
$ 1.92万
依托单位：
National Institute of Advanced Industrial Science and Technology
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2002
资助国家：
日本
起止时间：
2002 至 2004
项目状态：
已结题

项目摘要

We have developed a first-principles method for excited states of polymers using gaussian basis sets and proposed other efficient methods for studying excited states of solids, as summarized as the following.1.A computational method has been developed to calculate excited states of one-dimensional periodic systems using Hartree-Fock crystal orbital theory with gaussian basis sets, coupled-cluster theory, and equation-of-motion coupled-cluster theory. The method makes it possible to calculate excited states of polymers by taking electron correlation effects into accounts with high accuracy. The calculated excitation energies of polyethylene were well comparable with experiments.2.Two spin-density wave states were found in polydiacetylene between acetylene and butatriene structures from spin-unrestricted density functional calculations. The corresponding potential energy functions were different.3.A simplified computational method for excited states was proposed using time-dependent density functional theory and Bethe-Salpeter equation based on the assumption of a local electron-hole interaction.4.A computational method for excited states of strongly-correlated materials was proposed using dynamical mean-field theory and GW approximation. The method was successfully applied to electronic band structure of Ni. The agreement with the experimental band energies was excellent.5.Exchange-correlation kernel (fxc) in time-dependent density-functional theory was obtained from two-dimensional Hubbard model. By comparison with theoretical excitation spectrum it was demonstrated that fxc has strong energy dependence in the energy regions where there are many-body excitations.

We have developed a first-principles method for excited states of polymers using gaussian basis sets and proposed other efficient methods for studying excited states of solids, as summarized as the following.1.A computational method has been developed to calculate excited states of one-dimensional periodic systems using Hartree-Fock crystal orbital theory with gaussian basis sets, coupled-cluster theory, and equation-of-motion coupled-cluster theory.该方法可以通过将电子相关效应以高度准确性来计算聚合物激发态。聚乙烯的计算出的激发能与实验相当。2。从旋转无限密度功能计算的乙炔和丁烯结构之间的聚二乙烯中发现了旋转密度波状态。相应的势能函数不同。3.A激发态的简化计算方法是使用时间依赖性密度功能理论和基于局部电子孔相互作用的假设的时间依赖性密度功能理论和伯特 - 钙板方程的。4.a使用动态均值理论和GW近似值提出了强级强材料的激发态的计算方法。该方法成功地应用于Ni的电子带结构。与实验带能量的一致性非常出色。5。交换相关内核（FXC）在时间依赖性密度功能理论中的一致性是从二维哈伯德模型中获得的。通过与理论激发光谱相比，FXC在有多体激发的能量区域具有强大的能量依赖性。