Are multi-quasiparticle interactions important in molecular ionization?
Are multi-quasiparticle interactions important in molecular ionization?
复制标题
DOI：
10.1063/5.0044060
复制
发表时间：
2020-09
期刊：
影响因子：
--
通讯作者：
Carlos Mejuto-Zaera;Guorong Weng;Mariya Romanova;Stephen J. Cotton;K. B. Whaley;N. Tubman;V. Vlček
中科院分区：
文献类型：
--
作者：
Carlos Mejuto-Zaera;Guorong Weng;Mariya Romanova;Stephen J. Cotton;K. B. Whaley;N. Tubman;V. Vlček
光发射光谱直接探测单个电子状态，从单个激发到高能卫星，它们同时代表多个准粒子（QP）并编码有关电子相关的信息。光谱的第一性原理描述需要对所有多体效应进行有效而精确的处理。这对于其中单个QP图片分解的内价激发尤其具有挑战性。在这里，我们提供了完整的价态光谱的小闭壳层分子，探索独立和相互作用的准粒子制度，计算与完全相关的自适应采样配置相互作用方法。我们批判性地比较这些结果与多体微扰理论的计算，基于GW和顶点校正GWΓ方法。后者明确地解释了两个QP量子相互作用，这往往被忽视。我们表明，对于分子系统，顶点校正普遍提高了理论光谱，它是至关重要的准确预测的量子点，以及捕捉丰富的卫星结构的高能激发。GWr提供了所有相关能量尺度的统一描述。我们的结果表明，多QP制度对应于动力学相关，这可以通过微扰理论来描述。
Photo-emission spectroscopy directly probes individual electronic states, ranging from single excitations to high-energy satellites, which simultaneously represent multiple quasiparticles (QPs) and encode information about electronic correlation. The first-principles description of the spectra requires an efficient and accurate treatment of all many-body effects. This is especially challenging for inner valence excitations where the single QP picture breaks down. Here, we provide the full valence spectra of small closed-shell molecules, exploring the independent and interacting quasiparticle regimes, computed with the fully correlated adaptive sampling configuration interaction method. We critically compare these results to calculations with the many-body perturbation theory, based on the GW and vertex corrected GWΓ approaches. The latter explicitly accounts for two-QP quantum interactions, which have often been neglected. We demonstrate that for molecular systems, the vertex correction universally improves the theoretical spectra, and it is crucial for the accurate prediction of QPs as well as capturing the rich satellite structures of high-energy excitations. GWΓ offers a unified description across all relevant energy scales. Our results suggest that the multi-QP regime corresponds to dynamical correlations, which can be described via perturbation theory.