Pressure-induced hydrogen bonding:: Structure of D2S phase I′

The full structure of the high-pressure cubic phase I' of hydrogen sulfide has been solved using neutron diffraction data. The molecules are partially rotationally disordered about the [111] axes, as in phase II at ambient pressure but with markedly greater nonuniformity of thr toroidal D distribution. The changes in structure at the II --> I' transition signal the onset of significant pressure-induced hydrogen bonding.