报告摘要

Standard many-body perturbation theory is the foundation for many computational methods used today such as the GW approximation. However, it is well-known that this perturbation series breaks down in the presence of strong electron correlation. In this talk, I will present some recent progresses towards generalizing standard many-body perturbation theory (MBPT) for the electron correlation energy to the multi-reference case. Specifically, I will introduce a multi-reference generalization of random phase approximation (RPA) and the closely related second-order screened exchange (SOSEX) approximation based on diagrammatic resummation. Proof-of-concept results for typical molecules demonstrate that the resulting MR-RPA and MR-SOSEX successfully resolve the problems of the single-reference variants. This paves the way towards developing more reliable computational methods for strong correlation problems based on diagrammatic resummation.

报告人简介

　　李振东，男，北京师范大学77779193永利集团教授。2014年于永利集团获得理学博士学位，2014-2016年为美国普林斯顿大学博士后，2016-2018年为美国加州理⼯学院博⼠后。2019年加入北京师范大学77779193永利集团。2020年入选国家海外人才青年项目，同年度获中国化学会唐敖庆理论化学青年奖。主要从事高精度量子化学方法与程序开发、量子计算化学模拟。