1. Department of Chemistry, Beijing Normal University, Beijing 100875, PR China, Institute of Materia Medica and Department of Chemistry, School of Science, Beijing University of Chemical Technology, Beijing 100029 PR China, Eenheid Algemene Chemie (ALGC), Vrije Universiteit Brussel, Pleinlaan 2, B-1050 Brussels, Belgium, and Research Computing Center, University of North Carolina, Chapel Hill, North Carolina 27599-3420