1. Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803, United States
2. Discovery Pharmaceutical Sciences, Merck Research Laboratories, Merck & Co., Inc, West Point, Pennsylvania 19486, United States
3. Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, Maryland 20850, United States
4. NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
5. Biomolecular Measurement Division, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States
6. Malvern Panalytical, Westborough, Massachusetts 01581, United States
7. Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, United States