1. Department of Chemistry, 1102 Natural Science II, University of California, Irvine, California 92697, United States
2. Department of Chemistry, University of Basel, P.O. Box 3350, Mattenstrasse 24a, BPR 1096, CH-4002 Basel, Switzerland
3. Department of Molecular Biosciences and Biochemistry, University of California, Irvine, California 92697, United States
4. Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
5. Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States