水二聚体核心电离后依赖几何结构的非局域价电子屏蔽
Geometry-Dependent Nonlocal Valence Screening Following Core Ionization of the Water Dimer
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中文总结 AI 辅助
本研究以水二聚体为对象，引入关联移位启动实时Λ耦合簇理论，探究核心电离后的价电子屏蔽，发现核几何变化可调控多电子屏蔽，核心电离可作为电子通信的位点选择性探针。
中文摘要 AI 辅助
核心电离在空间上是局域的，但屏蔽所产生空穴的关联价电子响应未必如此。以水二聚体作为最小的氢键结合体系，我们探究受体位点O 1s电离是否会招募相邻供体分子上的价电子通道，以及质子位移如何重新分布该响应。我们引入关联移位启动实时Λ耦合簇理论，以连接核心空穴谱与轨道及片段分辨的屏蔽路径。在平衡构型下，卫星响应包含供体局域和类分子间电荷转移的贡献；当单体分离时，这两种贡献均被强烈抑制，证明其分子间起源。在固定核几何扫描中，延长氢键供体O-H键会使二者在卫星响应中的总占比近乎翻倍，而对固定核电子响应前约10 fs的分析显示，涉及供体局域价轨道的调制更强。更广泛而言，本研究表明局域核心电离可作为电子通信的位点选择性探针，卫星结构揭示核几何如何通过分子环境重新导向多电子屏蔽。
英文摘要
Core ionization is spatially localized, but the correlated valence response that screens the resulting hole need not be. Using the water dimer as a minimal hydrogen-bonded system, we ask whether acceptor-site O~1s ionization recruits valence channels on the neighboring donor molecule and how proton displacement redistributes that response. We introduce correlated shifted-start real-time $Λ$-coupled-cluster theory to connect the core-hole spectrum with orbital- and fragment-resolved screening pathways. At equilibrium, the satellite response contains donor-local and intermolecular charge-transfer-like contributions. Their intermolecular origin is supported by the strong suppression of both contributions when the monomers are separated. In a fixed-nuclei geometry scan, elongating the hydrogen-bonded donor O--H bond nearly doubles their combined share of the satellite response, while analysis of the first approximately 10~fs of the fixed-nuclei electronic response reveals stronger modulation involving a donor-localized valence orbital. More broadly, this work shows how localized core ionization can serve as a site-selective probe of electronic communication, with satellite structure revealing how nuclear geometry redirects many-electron screening through molecular environments.
