X-ray Raman scattering of liquids:Is water one liquid or two?


【講座題目】X-ray Raman scattering of liquids:Is water one liquid or two?


【講座地點】北京校部 主樓D603

【主 講 人】Faris Gel’mukhanov教授


Faris Gelmukhanov,瑞典皇家工學院教授,主要從事X射線科學、非線性光學和激光動力學領域的研究,包括強場激光與原子分子等量子體系相互作用的研究、X射線量子動力學理論研究、X射線光譜學研究以及時間分辨的X射線激光動力學研究等。已在Nature Physics, Nature Photonics, Nature Communications, PNAS, PRL, JACS, Angew等具有重要國際影響力的學術期刊發表論文250余篇,擔任多種國際期刊編委以及近25種國際期刊的審稿人,主持瑞典和歐盟等各類自然科學基金。


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.