1. Collaborative Innovation Center of Chemical Science and Engineering College of Chemistry Nankai University Tianjin 300071 China
2. Theoretical Division Los Alamos National Laboratory Los Alamos NM 87545 USA
3. Department of Chemistry and Biochemistry Utah State University 0300 Old Main Hill Logan UT 84322-0300 USA
4. Departments of Chemistry and Material Science Johns Hopkins University Baltimore MD 21218 USA
5. Institute of Inorganic Chemistry Karlsruhe Institute of Technology Engesserstr. 15 76131 Karlsruhe Germany