1. Department of Chemistry, 1102 Natural Sciences II, University of California at Irvine, Irvine, California 92697, United States
2. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
3. Department of Molecular Biosciences and Biochemistry, University of California at Irvine, Irvine, California 92697, United States
4. Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, United States