1. China-Australia Joint Laboratory for Functional Nanomaterials and Physics Department, Xiamen University, Xiamen 361005, China
2. ARC Centre of Excellence for Functional Nanomaterials, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia
3. Department of Physics, Jimei University, Xiamen 361021, China
4. Centre for Computational Molecular Science, University of Queensland, St Lucia, Brisbane, Queensland 4072, Australia