发表机构
École Polytechnique, Institut Polytechnique de Paris; European Theoretical Spectroscopy Facility (ETSF)（巴黎综合理工学院，巴黎理工学院; 欧洲理论光谱设施）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出多体微扰理论中屏蔽库仑相互作用的一致微扰展开，尤其关注Kohn-Sham系统周围的展开，并通过Hubbard二聚体验证其性能，表明基于精确Kohn-Sham成分的展开能同时获得良好的能量与光谱。
AI 中文摘要
多体微扰理论是计算光谱量以及总能量的强大框架。然而，该领域存在一个缺陷，即不同种类的近似方法会导致结果差异很大。我们提出了若干原则上精确的展开，并讨论如何一致地使用它们。我们专注于各自的屏蔽库仑相互作用中的前两阶。特别值得关注的是围绕Kohn-Sham系统的一致展开。我们利用对称的Hubbard二聚体在广泛的关联强度范围内展示了各种选择的性能。特别是，基于精确Kohn-Sham成分的展开，作为通往良好能量和良好光谱的有前景的途径脱颖而出。
英文摘要
Many-body perturbation theory is a powerful framework to calculate spectroscopic quantities, as well as the total energy. However, the field suffers from the fact that different flavors of approximations lead to a wide range of results. We present several in principle exact expansions and discuss how to use them consistently. We concentrate on the first two orders in the respective screened Coulomb interaction. Of special interest is a consistent expansion around the Kohn-Sham system. We illustrate the performance of the various choices using the symmetric Hubbard dimer over a wide range of correlation strength. In particular, the expansion based on exact Kohn-Sham ingredients stands out as a promising route towards good energies and good spectra.
Comments29 pages, 10 figures
