1. State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou 350002, Fujian, P. R. China
2. School of Physical Science and Technology & Key Laboratory for Magnetism and Magnetic Materials of the Ministry of Education, Lanzhou University, Lanzhou 730000, P. R. China
3. Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
4. State Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, P. R. China