Heidelberg 2015 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 20: Theory: Molecular Dynamics
MO 20.8: Vortrag
Donnerstag, 26. März 2015, 16:30–16:45, PH/SR106
Auger electron spectroscopy of liquid water: The role of intermolecular electronic relaxation and proton transfer — •Nikolai V. Kryzhevoi1, Petr Slavíček2, Bernd Winter3, and Lorenz S. Cederbaum1 — 1Theoretical Chemistry, University of Heidelberg, Germany — 2Department of Physical Chemistry, Institute of Chemical Technology, Prague, Czech Republic — 3Joint Laboratory for Ultrafast Dynamics in Solutions and at Interfaces, Helmholtz-Zentrum Berlin, Germany
Electronic relaxation of core-ionized water molecules in liquid is far more diverse and complex than anticipated, and extremely different from that in an isolated water molecule. This has been revealed by simulating Auger electron spectra of normal and heavy liquid water using ab initio and quantum dynamical methods and comparing the theoretical results with the available experimental data [1]. A core-ionized water molecule in the liquid phase, in addition to a local Auger process, relaxes through non-local energy- and charge-transfer, such as Intermolecular Coulombic Decay (ICD) [2] and Electron Transfer Mediated Decay (ETMD) [3]. These intermolecular decay processes play a surprisingly important role, especially ETMD which is considered for the first time in the core-level regime. The electronic relaxation is accompanied by ultrafast proton transfer dynamics [4] which enhances the efficiency of the non-local processes considerably. As a consequence, the double charge forming in the end of the electronic and nuclear relaxation tends to be distributed between different water monomers rather than be localized on a single molecular unit and various reactive oxygen species are created. Our study provides insight into the types and yields of these species. [1] P. Slavíček, B. Winter, L.S. Cederbaum, N.V. Kryzhevoi, J. Am. Chem. Soc. doi: 10.1021/ja5117588. [2] L.S. Cederbaum, J. Zobeley, F. Tarantelli, Phys. Rev. Lett. 79, 4778 (1997). [3] J. Zobeley, R. Santra, L.S. Cederbaum, J. Chem. Phys. 115, 5076 (2001). [4] S. Thürmer, M. Ončák, N. Ottosson, R. Seidel, U. Hergenhahn, S.E. Bradforth, P. Slavíček, B. Winter, Nature Chem. 5, 590 (2013).