1. Beijing National Laboratory for Molecular Sciences Institute of Chemistry Chinese Academy of Sciences Beijing 100190 China
2. University of Chinese Academy of Sciences Beijing 100049 China
3. Division of Physics and Applied Physics School of Physical and Mathematical Sciences Nanyang Technological University Singapore 637371 Singapore
4. Technical Institute of Physics and Chemistry Chinese Academy of Sciences Beijing 100190 China
5. Ji Hua Laboratory Foshan Guangdong 528000 P. R. China