1. School
of Pharmaceutical Sciences and Technology, Tianjin University, Tianjin 300072, P.R. China
2. Department
of Chemistry and Biochemistry, Texas Tech University, Lubbock, Texas 79409, United States
3. Institute
for Advanced Simulation, Jülich Supercomputing Centre, Forschungszentrum Jülich, Jülich 52428, Germany
4. Institute
for Theoretical Chemistry, University of Vienna, A-1090 Vienna, Austria
5. Department
of Chemistry, Princeton University, Princeton, New Jersey 08544-1009, United States
6. School
of
Engineering and Applied Science, Princeton University, Princeton, New Jersey 08544-5263, United States