1. State
Key Lab of Superhard Materials, Jilin University, Changchun 130012, P. R. China
2. College
of Physics and Electronic Information, Luoyang Normal University, Luoyang 471022, P. R. China
3. Beijing Computational Science Research Center, Beijing 10084, P. R. China
4. Department
of Chemistry and Biochemistry, California State University Northridge, California 91220, United States