1. Department of Physics and Astronomy and Center for Simulational Physics, University of Georgia, Athens, GA 30602, USA
2. State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, PR China
3. Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams (Ministry of Education), School of Physics, Dalian University of Technology, Dalian 116024, PR China
4. Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, NV 89154, USA
5. Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, NM 87545, USA