近日，瑞士洛桑联邦理工学院的Alexey Tal及其研究团队取得一项新进展。经过不懈努力，他们对基于有效顶点修正多体微扰理论的液态水绝对能级进行研究。相关研究成果已于2024年3月1日在国际知名学术期刊《美国科学院院刊》上发表。

该研究团队在多体摄动理论框架下，深入探讨了解决Γ顶点问题的重要性，成功超越了GW近似，精确计算了液态水的能级。在研究中，研究人员创引入一个高效的顶点函数，该函数在处理极化率和自能量时与GW近似相比不增加任何计算负担。此外，该研究所得到的带隙、电离势和电子亲和力与实验结果及杂化泛函的描述高度吻合。

这一研究的电子结构和介电屏蔽结果进一步促进了光学吸收光谱的精确描述，例如通过求解贝特-萨尔彼得方程即可得出。特别值得一提的是，研究人员还复现了实验中激子的峰值位置。

附：英文原文

Title: Absolute energy levels of liquid water from many-body perturbation theory with effective vertex corrections

Author: Tal, Alexey, Bischoff, Thomas, Pasquarello, Alfredo

Issue&Volume: 2024-3-1

Abstract: We demonstrate the importance of addressing the Γ vertex and thus going beyond the GW approximation for achieving the energy levels of liquid water in many-body perturbation theory. In particular, we consider an effective vertex function in both the polarizability and the self-energy, which does not produce any computational overhead compared with the GW approximation. We yield the band gap, the ionization potential, and the electron affinity in good agreement with experiment and with a hybrid functional description. The achieved electronic structure and dielectric screening further lead to a good description of the optical absorption spectrum, as obtained through the solution of the Bethe–Salpeter equation. In particular, the experimental peak position of the exciton is accurately reproduced.

DOI: 10.1073/pnas.2311472121

Source: https://www.pnas.org/doi/abs/10.1073/pnas.2311472121