中性激发的时变二阶格林函数理论。

Time-Dependent Second-Order Green's Function Theory for Neutral Excitations.

机构信息

Department of Chemistry, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.

Department of Physics, School of Science, Westlake University, Hangzhou, Zhejiang 310024, China.

出版信息

J Chem Theory Comput. 2022 Sep 13;18(9):5221-5232. doi: 10.1021/acs.jctc.2c00057. Epub 2022 Aug 30.

DOI:10.1021/acs.jctc.2c00057

PMID:36040050

Abstract

We develop a time-dependent second-order Green's function theory (GF2) for calculating neutral excited states in molecules. The equation of motion for the lesser Green's function (GF) is derived within the adiabatic approximation to the Kadanoff-Baym (KB) equation, using the second-order Born approximation for the self-energy. In the linear response regime, we recast the time-dependent KB equation into a Bethe-Salpeter-like equation (GF2-BSE), with a kernel approximated by the second-order Coulomb self-energy. We then apply our GF2-BSE to a set of molecules and atoms and find that GF2-BSE is superior to configuration interaction with singles (CIS) and/or time-dependent Hartree-Fock (TDHF), particularly for charge-transfer excitations, and is comparable to CIS with perturbative doubles (CIS(D)) in most cases.

摘要

我们开发了一种用于计算分子中中性激发态的时变二阶格林函数理论（GF2）。在绝热近似到 Kadanoff-Baym（KB）方程的范围内，通过对自能进行二级 Born 近似，推导出较小格林函数（GF）的运动方程。在线性响应 regime 下，我们将时变 KB 方程重铸为类似 Bethe-Salpeter 的方程（GF2-BSE），其中核由二级库仑自能近似。然后，我们将 GF2-BSE 应用于一组分子和原子，并发现 GF2-BSE 优于组态相互作用与单重态（CIS）和/或含时 Hartree-Fock（TDHF），特别是对于电荷转移激发，并且在大多数情况下与微扰双组态 CIS（CIS(D)）相当。