Experimental phase transition mapping for hydrogen above 300 K up to 300 GPa

We report a phase diagram mapping for solid hydrogen based on several thousands of Raman spectroscopic data points obtained at simultaneous high-pressure and -temperature (PT) experiments. Information about behavior in the range 300 K up to melting line 0--300 GPa has remained almost unknown date; therefore, revealing it is very desirable. A network analysis isothermal isobaric dependencies various modes been used; discontinuities these dependencies, plus mode appearance/disappearance provide evidence transitions. These transition show self-consistency have used outline possible boundaries this PT region. Evidence we found shows may experience gradual molecular dissociation process before its metallization.