1. Kuang
Yaming Honors School, Nanjing University, Nanjing, P.R. China
2. Institute
for Computational Molecular Science, Temple University, 1900 North
12th Street, Philadelphia, Pennsylvania 19122-6078, United States
3. School
of Chemistry and Chemical Engineering, Key Laboratory of Mesoscopic
Chemistry of Ministry of Education, Institute of Theoretical and Computational
Chemistry, Nanjing University, Nanjing, P.R. China
4. Department
of Physics, Temple University, 1900 North 12th Street, Philadelphia, Pennsylvania 19122-6078, United States