1. School of Chemistry and Biochemistry, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
2. NSF-NASA Center for Chemical Evolution, Atlanta, Georgia 30332-0400, United States
3. Center for Computational Molecular Science and Technology, Georgia Institute of Technology, Atlanta, Georgia 30332-0400, United States
4. Department of Biological Sciences and Center for Structural Biology, Vanderbilt University, Nashville, Tennessee 37235, United States
5. School of Computational Science and Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0765, United States