1. Linac Coherent Light Source (LCLS), SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
2. Max-Planck-Institut für Medizinische Forschung, Jahnstrasse 29, 69120 Heidelberg, Germany.
3. Max Planck Advanced Study Group, Center for Free-Electron Laser Science, Notkestrasse 85, 22607 Hamburg, Germany.
4. Center for Free-Electron Laser Science, Deutsches Elektronen-Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany.
5. Department of Physics, Arizona State University, Tempe, AZ 85287, USA.
6. Particle Physics and Astrophysics, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
7. Department of Physics, Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY 14853, USA.
8. Wilson Laboratory, Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, USA.
9. Electrical and Computer Engineering, State University of New York (SUNY) Oswego, Oswego, NY 13126, USA.
10. The Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723, USA.
11. Nikhef, National Institute for Subatomic Physics, Science Park 105, 1098 XG Amsterdam, Netherlands.
12. European Synchrotron Radiation Facility, 38043 Grenoble Cedex, France.
13. Department of Chemistry and Molecular Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden.
14. PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA.
15. Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287–1604, USA.
16. University of Hamburg, Luruper Chaussee 149, 22761 Hamburg, Germany.
17. Joint Laboratory for Structural Biology of Infection and Inflammation, Institute of Biochemistry and Molecular Biology, University of Hamburg, and Institute of Biochemistry, University of Lübeck, at DESY, Hamburg, Germany.
18. German Centre for Infection Research, University of Lübeck, 23538 Lübeck, Germany.
19. Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan 3 (Box 596), SE-751 24 Uppsala, Sweden.