1. Department of Chemistry, and the Center of Theoretical Chemistry Study, Nankai University, Tianjin, 300071, P. R. China, Research Institute for Computational Sciences (RICS), and Research Consortium for Synthetic Nano-Function Materials Project (SNAF), National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 2, 1-1-1 Umezono, Tsukuba, Ibaraki 305-8568, Japan, and Institute of Materials Science, University of Tsukuba, Tsukuba, Ibaraki 305-8573, Japan