1. Center for High Pressure Science and Technology Advanced Research, Shanghai 201203, China
2. High Pressure Synergetic Consortium, Geophysical Laboratory, Carnegie Institute of Washington, Argonne, Illinois 60439, USA
3. Condensed Matter Science and Technology Institute, Harbin Institute of Technology, Harbin 150080, China
4. Department of Mathematics and Materials Research Institute, The Pennsylvania State University, University Park, Pennsylvania 16802, USA