1. Department
of Chemistry, Kent State University, 1787 Summit Street, Kent, Ohio 44242, United States
2. Department of Physics, University of Houston, 617 Science & Research Building 1, Houston, Texas 77204, United States
3. Computation
Institute, University of Chicago, 5735 South Ellis Avenue, Chicago, Illinois 60637, United States
4. Center
for Theoretical Biological Physics, Rice University, 6500 Main
Street, Houston, Texas 77030, United States