1. Department
of Chemistry, Key Laboratory of Environmentally Friendly Chemistry
and Applications of Ministry of Education, Xiangtan University, Hunan
Province, Xiangtan 411105, P. R. China
2. Hunan
Key Laboratory for Computation and Simulation in Science and Engineering,
Institute for Computational and Applied Mathematics, Xiangtan University, Hunan
Province, Xiangtan 411105, P. R. China
3. Department
of Chemistry and Nebraska Center for Materials and Nanoscience, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, United States