1. Advanced Photon Source, Argonne National Laboratory, 9700 S Cass Ave., Argonne, Illinois 60439, USA
2. Department of Geology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
3. High Pressure Collaborative Access Team, Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, USA
4. Institute of Physics, Chinese Academy of Sciences, Beijing 10090, People’s Republic of China
5. Department of Geology Sciences, The University of Texas at Austin, Austin, Texas 78712, USA