1. Department of Chemistry, Dalian University of Technology, Dalian 116024, China, State Key Laboratory of Materials Modification by Laser, Electron, and Ion Beams & College of Advanced Science and Technology, Dalian University of Technology, Dalian 116024, China, Department of Physics, Huaiyin Institute of Technology, Jiangsu 223001, China, and Department of Chemistry and Center for Computational Chemistry, University of Georgia, Athens, Georgia 30602