1. National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, Peoples Republic of China, Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, and Lehrstuhl für Physikalische Chemie II and Interdisciplinary Center for Molecular Materials, and Lehrstuhl für Theoretische Chemie, Universität Erlangen-Nürnberg, Egerlandstr. 3, 91058 Erlangen, Germany