1. Institute of Biomedical Research, Yunnan University, Kunming 650500, Yunnan, P. R. China
2. Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ONL8S 4M1, Canada
3. Qingdao Institute for Theoretical and Computational Sciences, Shandong University, Qingdao 266237, Shandong, P. R. China
4. Research Computing Center, University of North Carolina, Chapel Hill, North Carolina 27599-3420, USA
5. Department of Chemistry, University of North Carolina, Chapel Hill, North Carolina 27599-3290, USA