1. Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, Natural Sciences Building 3328, La Jolla, California92093, United States
2. Department of Physics, University of California, San Diego, 9500 Gilman Drive, Mayer Hall Addition 4561, La Jolla, California92093, United States
3. Department of Chemistry, The University of Texas at Austin, 105 E. 24th St. Stop A5300, Austin, Texas78712−1224, United States
4. Department of Molecular Biology, School of Biological Sciences, University of California, San Diego, La Jolla, California92093, United States
5. X-ray Science Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois60439, United States