1. Center for High Pressure Science and Technology Advanced Research, Beijing 100094, P. R. China
2. Key Laboratory of Weak-Light Nonlinear Photonics and School of Physics, Nankai University, Tianjin 300071, P. R. China
3. J-PARC Center, Japan Atomic Energy Agency, Tokai, Ibaraki 319-1195, Japan
4. Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba, Ibaraki 305-0801, Japan
5. Institute of Materials Structure Science, High Energy Accelerator Research Organization (KEK), Tokai, Ibaraki 319-1106, Japan
6. Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, P. R. China
7. Spallation Neutron Source Science Center, Dongguan 523803, P. R. China
8. CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China