1. CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China
2. Institute for Computational Molecular Science, Temple University, Philadelphia, Pennsylvania 19122, United States
3. Department of Chemistry, Yeshiva University, New York, New York 10033, United States
4. Department of Chemistry, Michigan State University, East Lansing, Michigan 48824-1322, United States