1. Department of Chemistry and Biochemistry, University of Oklahoma, 101 Stephenson Pkwy, Norman, Oklahoma 73019, USA
2. Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas 76019, USA
3. Q-Chem, Inc., 6601 Owens Drive, Suite 105, Pleasanton, California 94588, USA
4. National Institutes of Health–National Heart, Lung and Blood Institute, Laboratory of Computational Biology, Bethesda, Maryland 20892, USA
5. Department of Physics and Astronomy, University College London, London WC1E 6BT, United Kingdom