1. College of Chemistry and Materials ScienceThe Key Laboratory of Functional Molecular SolidsMinistry of Education, Anhui Laboratory of Molecular-Based MaterialsThe Key Laboratory of Electrochemical Clean Energy of Anhui Higher, Education InstitutesAnhui Normal University NO. 189 South Jiuhua Road Wuhu 241002 P.R. China
2. Nano and Molecular Systems Research UnitUniversity of Oulu P.O. Box 3000 FIN-90014 Oulu Finland
3. Department of PhysicsUniversity of Helsinki P.O. Box 64 FI-00014 Helsinki Finland