The quest for the hydrogen-disordered counterpart of ice II

Water displays a highly complex phase diagram that is key to a range of critical processes, from the evolution of icy moons to that of the Earth's hydrosphere and even of life itself. Using ISIS facilities, our group has made tremendous progress exploring the phase diagram of ice. We discovered three new phases of ice labelled ices XIII, XIV and XV which are the hydrogen-ordered counterparts of ices V, XII and VI. This proposal focusses on ice II which is special in the sense that it is the only phase of ice for which the hydrogen-disordered counterpart has not been discovered yet. Using helium gas as a trick to stabilise ice II and a chemical hydrogen-disordering agent which we recently discovered, we now aim to finally prepare the so far illusive hydrogen-disordered ice II and to solve one of the last remaining mysteries in the phase diagram of water.