1. School of Materials Science and Engineering, Nanyang Technological University, Singapore 639798, Singapore
2. State Key Laboratory of Crystal Materials, Shandong University, Jinan, Shandong 250100, China
3. Fujian Institute of Research on the Structure
of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002, China
4. Bruker Scientific Technology Co. Ltd, Beijing 100081, China
5. Division
of Chemistry and Biological Chemistry, School of Physical and Mathematical
Sciences, Nanyang Technological University, Singapore 637371, Singapore