1. Center for High Pressure Science and Technology Advanced Research, Beijing 100094, P. R. China
2. Faculty
of Chemistry, Adam Mickiewicz University, Umultowska 89b, 61-614 Poznan, Poland
3. J-PARC
Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
4. College
of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
5. HPSynC,
Geophysical Laboratory, Carnegie Institution of Washington, Argonne, Illinois 60439, United States
6. Geophysical
Laboratory, Carnegie Institution of Washington, Washington, DC 20015, United States