1. Department
of Physics and Astronomy, Wayne State University, Detroit, Michigan 48201, United States
2. Center
for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Computer
Science and Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. Biology and
Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
5. Chemical
and Engineering Materials Division, Oak Ridge National Laboratory, Oak
Ridge, Tennessee 37831, United States
6. Institute of Natural Science & Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240, China