a
State Key Laboratory of Mesoscopic Physics and Department of Physics, Peking University, Beijing 100871, P. R. China
E-mail: jinglu@pku.edu.cn
b
Department of Theoretical and Computational Molecular Science, Institute for Molecular Science, Okazaki 444-8585, Japan
c
Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, P. R. China