1. Center for Free-Electron Laser Science CFEL, Deutsches Elektronen-Synchrotron DESY, Notkestraße 85, Hamburg 22607, Germany
2. Chemical Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
3. Department of Physics and James Franck Institute, The University of Chicago, Chicago, Illinois 60637, United States
4. Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinous 60439, United States
5. Department of Chemistry, Northwestern University, 2145 N. Sheridan Rd., Evanston, Illinois 60208, United States
6. Department of Applied Physics, Tokyo University of Agriculture and Technology, Tokyo 184-8588, Japan
7. Department of Physics and Astronomy, Uppsala University, Box 516, Uppsala SE-75120, Sweden
8. Laboratoire de Chimie Physique-Matière et Rayonnement, LCPMR, Sorbonne Université, CNRS, Paris F-75005, France
9. LCLS, SLAC, Menlo Park, California 94025, United States
10. School of Chemistry, Chemical Engineering and Biotechnology, and School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore 637371, Singapore
11. Department of Physics, Universität Hamburg, Notkestraße 9, Hamburg 22607, Germany