1. National Laboratory of Superhard Materials, Jilin University, Changchun 130012, People’s Republic of China; and College of Physics and Electronic Information, Luoyang Normal College, Luoyang 471022, People’s Republic of China.
2. College of Chemistry and Chemical Engineering, Luoyang Normal College, Luoyang 471022, People’s Republic of China.
3. Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065 People’s Republic of China.