1. Center for Biophysics and Quantitative Biology; University of Illinois; Urbana IL 61801 USA
2. Department of Chemistry and Institute for Biophysical Dynamics, Computation Institute, James Franck Institute; University of Chicago; Chicago IL 60637 USA
3. Department of Chemistry and Biochemistry and Institute for Physical Science and Technology; University of Maryland; College Park MD 20742 USA
4. Departments of Chemistry and Physics; University of Illinois; Urbana IL 61801 USA
5. Department of Physics; Ariel University; Ariel 40770 Israel