论文标题
模拟用相对论量子嵌入计算的卤化物种的核心电子结合能
Simulating core electron binding energies of halogenated species adsorbed on ice surfaces and in solution with relativistic quantum embedding calculations
论文作者
论文摘要
在这项工作中，我们研究了环境对吸附在冰面上的氯化氢和氯离子以及水滴中氯离子的影响。 In our approach, we combine a density functional theory (DFT) description of the ice surface with that of the halogen species with the recently developed relativistic core-valence separation equation of motion coupled cluster (CVS-EOM-IP-CCSD) via the frozen density embedding formalism (FDE), to determine the K and L$_{1,2,3}$ edges of chlorine.我们的计算通过经典分子动力学模拟的快照结合了温度效应，可证明可以在从液体（水滴）转移到界面（冰质准 - 液体层）环境时重现Cl $^ - $变化的实验趋势。我们的模拟产生水价带的结合能与实验一致，而在液滴和冰表面之间的变化很小。对于卤化物核心结合能，尽管在水滴和冰上发现理论和实验之间的良好一致性是在理论和实验之间良好的一致性的总体趋势。另一方面，对于HCL，当我们考虑将H-CL键或多或少完整的结构模型考虑时，实验和计算出的核心结合能之间存在显着差异。对允许预脱离前和解离结构的模型的分析表明，在Cl $^-$ snd HCl之间实验观察到的结合能中的化学位移会重现H $^+$（以H $ _3 $ o $^+$的形式）和Cl $^ - $由大约4-6 A. A. A. A. A.
In this work we investigate the effects of the environment on the X-ray photoelectron spectra of hydrogen chloride and the chloride ions adsorbed on ice surfaces, as well as of chloride ions in water droplets. In our approach, we combine a density functional theory (DFT) description of the ice surface with that of the halogen species with the recently developed relativistic core-valence separation equation of motion coupled cluster (CVS-EOM-IP-CCSD) via the frozen density embedding formalism (FDE), to determine the K and L$_{1,2,3}$ edges of chlorine. Our calculations, which incorporate temperature effects through snapshots from classical molecular dynamics simulations, are shown to reproduce experimental trends in the change of the core binding energies for Cl$^-$ upon moving from a liquid (water droplets) to an interfacial (ice quasi-liquid layer) environment. Our simulations yield water valence band binding energies in good agreement with experiment, and that vary little between the droplets and the ice surface. For the halide core binding energies there is an overall trend of overestimating experimental values, though good agreement between theory and experiment is found for Cl$^-$ in water droplets and on ice. For HCl on the other hand there are significant discrepancies between experimental and calculated core binding energies when we consider structural models which maintain the H-Cl bond more or less intact. An analysis of models that allow for pre-dissociated and dissociated structures suggests that experimentally observed chemical shifts in binding energies between Cl$^-$ snd HCl would reqire that H$^+$ (in the form of H$_3$O$^+$) and Cl$^-$ are separated by roughly 4-6 A.
