1. School of Foundational Education, University of Health and Rehabilitation Sciences, Qingdao 266113, China
2. Qingdao Institute for Theoretical and Computational Sciences, Institute of Frontier and Interdisciplinary Science, Shandong University, Qingdao, Shandong 266237, P. R. China
3. Department of Materials Science and Engineering, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
4. Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
5. Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States