1. Department of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, Jiangsu 210094, P. R. China
2. Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
3. Department of Mechanical Engineering, The University of Utah, Salt Lake City, UT 84112, USA
4. State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun 130012, P. R. China
5. Department of Physics and Astronomy and Department of Electrical and Computer Engineering, Vanderbilt University, Nashville, TN 37235, USA