1. Department of Applied Physics and Institution of Energy and Microstructure, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, P.R. China
2. Key Laboratory of Computational Physical Sciences (Ministry of Education), State Key Laboratory of Surface Physics, and Department of Physics, Fudan University, Shanghai 200433, P.R. China
3. School of Science, Nanjing Forestry University, Nanjing, Jiangsu 210037, P.R. China
4. Beijing Computational Science Research Center, Beijing 100193, P.R. China
5. Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093, P.R. China