1. Department of Chemistry, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
2. Department of Physics, University of Michigan, 450 Church Street, Ann Arbor, Michigan 48109-1040, United States
3. Department of Biophysics, University of Michigan, 930 N University Avenue, Ann Arbor, Michigan 48109-1055, United States
4. Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, United States
5. Femtosecond X-ray Experiments Group, European XFEL, Holzkoppel 4, 22869 Schenefeld, Germany