1. Department of Chemistry, Duke University, Durham, North Carolina 27708, United
States
2. Department of Chemistry, Northwestern University, Evanston, Illinois 60208,
United States
3. Department
of Chemistry and Chemical
Biology, Cornell University, Ithaca, New
York 14853, United States
4. Department of Biochemistry, Duke University, Durham, North Carolina 27708, United
States
5. Department of Physics, Duke University, Durham, North Carolina 27708, United
States