1. Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
2. Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. Department of Chemical and Biomolecular Engineering, University of Tennessee, Knoxville, Tennessee 37996, United States