1. Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden
2. Department of Physical Chemistry, University of Chemistry and Technology, Technická 5, Prague 6, 166 28, Czech Republic
3. Center for Free-Electron Laser Science, DESY, Notkestraße 85, 22607 Hamburg, Germany
4. Molecular Physics Department, Fritz-Haber-Institut der Max-Planck-Gesellschaft, Faradayweg 4-6, 14195 Berlin, Germany
5. Institut für Kernphysik, Goethe-Universität Frankfurt am Main, Max-von-Laue-Straße 1, 60438 Frankfurt am Main, Germany
6. MAX IV Laboratory, Lund University, Box 118, SE-22100 Lund, Sweden
7. Department of Chemistry and Industrial Chemistry, University of Pisa, Via Giuseppe Moruzzi 13, 56124 Pisa, Italy
8. Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex, Paris, France
9. Department of Locally-Sensitive & Time-Resolved Spectroscopy, Helmholtz-Zentrum Berlin für Materialien und Energie, 14109 Berlin, Germany