1. Chemical
Sciences and Engineering Division, Argonne National Laboratory, Lemont, Illinois 60439, United States
2. Department
of Chemistry, Northwestern University, Evanston, Illinois 60208, United States
3. Department
of Chemistry, University of Washington, Seattle, Washington 98195, United States
4. Physics
Department, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
5. LCLS, SLAC National Laboratory, Menlo Park, California 94025, United States