Hua Tai, Kurkowski Lucas, Lopata Kenneth
Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
Center for Computation and Technology, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
J Phys Chem A. 2025 Aug 28;129(34):7742-7750. doi: 10.1021/acs.jpca.5c01706. Epub 2025 Aug 13.
Rapid X-ray ionization of a core electron is known to induce the attosecond motion of valence electrons; however, the effect of core-hole shape on the triggered dynamics remains relatively unknown. In this work, the sub-four fs response of prototypical functionalized/heterocyclic/polycyclic molecules was simulated using real-time time-dependent density functional theory (RT-TDDFT), a sudden approximation core-hole, and phenomenologically Auger-Meitner (AM) decay. These molecules included fluorobenzene, chlorobenzene, bromobenzene, phenol, thiophenol, pyridine, phosphorus, and azulene. It is observed that the valence electron dynamics are essentially independent of the core-hole created, provided that it is ionized from an inner-shell orbital and not an inner-valence orbital. This has broad implications for free-electron laser studies of X-ray pumped attosecond processes since the flexibility in edge allows for a wide range of experimental modalities, core-holes with longer AM lifetimes, and molecular targets.
已知核心电子的快速X射线电离会引发价电子的阿秒运动；然而，核心空穴形状对触发动力学的影响仍然相对未知。在这项工作中，使用实时含时密度泛函理论（RT-TDDFT）、突然近似核心空穴和唯象俄歇-迈特纳（AM）衰变，模拟了典型功能化/杂环/多环分子的亚四飞秒响应。这些分子包括氟苯、氯苯、溴苯、苯酚、苯硫酚、吡啶、磷和薁。据观察，只要核心空穴是从内壳层轨道而非内价层轨道电离产生的，价电子动力学基本上就与所产生的核心空穴无关。这对X射线泵浦阿秒过程的自由电子激光研究具有广泛的意义，因为边缘的灵活性允许采用多种实验模式、具有更长AM寿命的核心空穴以及分子靶标。
