1. Department
of Chemistry, New York University, 100 Washington Square East, New York, New York 10003, United States
2. Theoretical
Biology and Biophysics Group, Theoretical Division, Los Alamos National Laboratory, Bikini Atoll Road, SM 30, Los Alamos, New Mexico 87545, United States
3. Courant
Institute of Mathematical Sciences, New York University, 251 Mercer Street, New York, New York 10012, United States