1. Multiscale Computational Materials Facility, College of Materials Science and Engineering, Fuzhou University, Fuzhou 350108, P. R. China
2. School of Materials Science and Engineering, Beihang University, Beijing 100191, P. R. China
3. School of Physics, Zhejiang University, Hangzhou 310058, P. R. China
4. Department of Physics, University of Hamburg, D-20355 Hamburg, Germany