1. College
of Materials, Xiamen University, 361005 Xiamen, P. R. China
2. School
of Materials Science and Engineering, and Center for Integrated Computational
Materials Engineering, International Research Institute for Multidisciplinary
Science, Beihang University, 100191 Beijing, P. R. China
3. Condensed
Matter Theory Group, Department of Physics and Astronomy, Uppsala University, 75120 Uppsala, Sweden