1. Institute of Theoretical Chemistry, College of Chemistry, Jilin University, 130023 Changchun, P. R. China
2. College of Chemistry, Jilin University, 130023 Changchun, P. R. China
3. College of Chemistry and Chemical Engineering, Inner Mongolia University, 010021 Hohhot, P. R. China
4. Institute of Solid State Physics, University of Latvia, 8 Kengaraga Str., Riga LV1067, Latvia
5. School of Materials Science and Physics, China University of Mining and Technology, 221116 Xuzhou, P. R. China