Supplement Figures S1-S8 and Table S1-S5

high-pressure Raman spectroscopy of CuInP2Se6 under hydrostatic condition and their correspondent pressure-dependent Raman shifts and FWHMs under different hydrostatic environment; pressure-dependent relaxation frequency; high-temperature Raman scattering results and their enlarged views at 1.0 and 1.7 GPa, and their correspondent temperature-dependent Raman shifts and Raman FWHMs; the fitting results of pressure-dependent Raman shifts, FWHMs and activation energy; the fitting results of temperature-dependent Raman shifts; the Curie temperature and its correspondent slope for CuInP2S6 and CuInP2Se6.