報告摘要

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.

報告人簡介

　　李振東，男，北京師範大學化學學院教授。2014年于beat365獲得理學博士學位，2014-2016年為美國普林斯頓大學博士後，2016-2018年為美國加州理⼯學院博⼠後。2019年加入北京師範大學化學學院。2020年入選國家海外人才青年項目，同年度獲中國化學會唐敖慶理論化學青年獎。主要從事高精度量子化學方法與程序開發、量子計算化學模拟。