分子多通道戴森方程与代数图构造方法的基准测试
Benchmark of Multi-Channel Dyson Equation and Algebraic Diagrammatic Construction Methods for molecules
AI总结：
本文对23个小分子的58个电离势，基准测试戴森-ADC(2)-X、ADC(3)及屏蔽(3,1)-MCDE，发现nD-ADC(3)与戴森-ADC(3)偏差约0.1 eV，质疑nD近似可靠性，且屏蔽(3,1)-MCDE性能优于未屏蔽版本。
AI中文摘要：
戴森-代数图构造（ADC）与多通道戴森方程（MCDE）形式主义明确利用多粒子通道构建单粒子格林函数的关联理论，其构造产生半正定谱函数。MCDE严格基于戴森形式主义，而多数ADC计算在非戴森（nD）框架中进行，该框架将电子附着与脱离部分解耦。我们对23个小分子的58个电离势进行基准测试，这些分子拥有近全组态相互作用参考数据，测试对象为戴森-ADC(2)-X（等价于(3,1)-MCDE）与ADC(3)近似。戴森-ADC(3)与nD-ADC(3)的比较显示两者存在约0.1 eV的偏差，这引发了对nD近似可靠性的质疑。我们表明戴森-ADC对第一电离势、半价及半芯跃迁的精度相似。最后，我们还对屏蔽所有 ladder 相互作用的屏蔽(3,1)-MCDE进行基准测试，结果显示其相比未屏蔽版本有所提升。
英文摘要：
The Dyson-algebraic diagrammatic construction (ADC) and the multi-channel Dyson equation (MCDE) formalisms explicitly leverage multi-particle channels to formulate correlated theories of the single-particle Green's function that produce positive semi-definite spectral functions by construction. While the MCDE is strictly rooted in the Dyson formalism, most ADC calculations are performed in the non-Dyson (nD) framework that decouples electron attachment and detachment sectors. We benchmark the Dyson-ADC(2)-X [that is equivalent to the (3,1)-MCDE] and ADC(3) approximations on a set of 58 ionization potentials of 23 small molecules for which near-full configuration interaction reference data exist. Comparison of Dyson- to nD-ADC(3) reveals deviations of the order of 0.1 eV between both methods, calling into question the reliability of the nD approximation. We show that Dyson-ADC gives similar accuracy for first IPs as for semi-valence and semi-core transitions. Finally, we also benchmark the screened (3,1)-MCDE that screens all ladder interactions, and show that it improves over its unscreened counterpart.
