1. College of Life Sciences, Research Center
of Analytical Instrumentation, Sichuan University, Chengdu, Sichuan 610064, P. R. China
2. Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
3. Computer Science & Mathematics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, United States
4. Department
of Chemistry, Georgetown University, 37th and O Streets, NW, Washington, D.C. 20057, United States