Figure 1. Formation enthalpy per atom, H, of crystal structures obtained by the application of the GA technique to the H5S2 stoichiometry.
H5S2 takes a disorderly mixed structure of H2S and H2 molecules at 50 GPa, and it transforms into a monoclinic C2/m at 64 GPa and then into a triclinic P1 with mixed H2S and H3S structure at 92 GPa.