1. Department of Chemistry, University of Connecticut, 55 North Eagleville Rd., Storrs, Connecticut 06269-3060, United States
2. Department of Physics and Astronomy, Valparaiso University, Valparaiso, Indiana 46383, United States
3. Center for Structural Molecular Biology, Oak Ridge National Laboratory, P.O. Box 2008
MS-6430, Oak Ridge, Tennessee 37831-6430, United States