《LDA+U第一性原理方法.ppt

下载文档 降价啦

16
0
约 59页
2016-12-29 发布于北京
举报
版权申诉
保障服务

《LDA+U第一性原理方法.ppt

1、本文档共59页，可阅读全部内容。
2、有哪些信誉好的足球投注网站（book118）网站文档一经付费（服务费），不意味着购买了该文档的版权，仅供个人/单位学习、研究之用，不得用于商业用途，未经授权，严禁复制、发行、汇编、翻译或者网络传播等，侵权必究。
3、本站所有内容均由合作方或网友上传，本站不对文档的完整性、权威性及其观点立场正确性做任何保证或承诺！文档内容仅供研究参考，付费前请自行鉴别。如您付费，意味着您自己接受本站规则且自行承担风险，本站不退款、不进行额外附加服务；查看《如何避免下载的几个坑》。如果您已付费下载过本站文档，您可以点击这里二次下载。
4、如文档侵犯商业秘密、侵犯著作权、侵犯人身权等，请点击“版权申诉”（推荐），也可以打举报电话：400-050-0827(电话支持时间：9:00-18:30)。

Introduction to LDA+U method and applications to transition-metal oxides:Importance of on-site Coulomb interaction U 鄭弘泰國家理論中心 (清華大學) 28 Aug, 2003, 東華大學 Outline DFT, LDA (LDA, LSDA, GGA) Insufficiencies of LDA How to improve LDA Self-interaction correction (SIC) LDA+U method Applications of LDA+U on various transition-metal oxides Conclusions Density Functional Theory (DFT)Hohenberg-Kohn Theorem, PR136(1964)B864 The ground-state energy of a system of identical spinless fermions is a unique functional of the particle density. This functional attains its minimum value with respect to variation of the particle density subject to the normalization condition when the density has its correct values. Local density approximation (LDA)Kohn-Sham scheme PR140(1965)A1133 Insufficiencies of LDA Poor eigenvalues, PRB23, 5048 (1981) Lack of derivative discontinuity at integer N, PRL49, 1691 (1982) Gaps too small or no gap, PRB44, 943 (1991) Spin and orbital moment too small, PRB44, 943 (1991) Especially for transition metal oxides Attempts on improving LDA Self-interaction correction (SIC) PRB23(1981)5048, PRL65(1990)1148 Hartree-Fock (HF) method, PRB48(1993)5058 GW approximation (GWA), PRB46(1992)13051, PRL74(1995)3221 LDA+Hubbard U (LDA+U) method, PRB44(1991)943, PRB48(1993)16929 Local density approximation (LDA)Kohn-Sham scheme PR140(1965)A1133 Self-interaction correction (SIC) Perdew and Zunger, PRB23(1981)5048 Basic idea of LDA+U PRB 44 (1991) 943, PRB 48 (1993) 169 Delocalized s and p electrons : LDA Localized d or f electrons : +U using on-site d-d Coulomb interaction (Hubbard-like term) UΣi≠jninj instead of averaged Coulomb energy UN(N－1)/2 When to use LDA+U Systems that LDA gives bad results Narrow band materials : U≧W Transition-metal oxides Localized electron systems Strongly correlated materials Insulators ….. How to calculate U and J PRB 39 (1989) 9028 Co