1. Neutron Scattering Science Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
2. Molecular and Structural Biochemistry Department, North Carolina State University, Raleigh, North Carolina 27695, United States
3. National Institute of Standards and Technology, Center for Neutron Research, Gaithersburg, Maryland 20899, United States
4. Computer Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States