1. Qingdao Institute for Theoretical and Computational Sciences, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, P. R. China
2. Oden Institute for Computational Engineering and Sciences, University of Texas at Austin, Austin, Texas 78712, United States
3. Department of Chemistry, University of Texas at Austin, Austin, Texas 78712, United States