【讲座题目】X-ray Raman scattering of liquids:Is water one liquid or two?

【讲座时间】2019年8月29日（周四）10:00-11:30

【讲座地点】北京校部 主楼D603

【主 讲 人】Faris Gel’mukhanov教授

【主讲人简介】

Faris Gelmukhanov，瑞典皇家工学院教授，主要从事X射线科学、非线性光学和激光动力学领域的研究，包括强场激光与原子分子等量子体系相互作用的研究、X射线量子动力学理论研究、X射线光谱学研究以及时间分辨的X射线激光动力学研究等。已在Nature Physics, Nature Photonics, Nature Communications, PNAS, PRL, JACS, Angew等具有重要国际影响力的学术期刊发表论文250余篇，担任多种国际期刊编委以及近25种国际期刊的审稿人，主持瑞典和欧盟等各类自然科学基金。

【内容简介】

Local probes of the electronic ground and valence excited states are essential for understanding hydrogen bonding in aqueous environments. Vibrational infra-red (IR) spectroscopy is an established technique for investigations of hydrogen bonding. High-resolution X-ray absorption spectroscopy and resonant inelastic X-ray scattering (RIXS) offers a complement to IR vibrational spectroscopy. The propagation of the nuclear wave packet in dissociative core-excited stateresults in the long vibrational progression seen in both theory and experiment. This gives great advantage of RIXS in comparison with IR spectroscopy which probes mainly the first OH excitation. We show how different resonant inelastic X-ray scattering (RIXS) channels deliver separate information; about the local structure via long-range dynamics in quasi-elastic RIXS and about short-range dynamics, which is much less sensitive to the structure, in the electronically inelastic 1b1 and 4a’’ channel in water and methanol, respectively. Our theoretical framework is composed of classical ab initio molecular dynamics (MD) simulations, calculation of local potential energy surfaces from the sampled configurations, and quantum wave packet modeling of the nuclear motion in relevant degrees of freedom.