1. Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg,
Germany
2. The Hamburg Center for Ultrafast Imaging, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg,
Germany
3. Department of Chemistry, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg,
Germany
4. Department of Physics, Universität Hamburg, Luruper Chaussee 149, 22761 Hamburg,
Germany