Effect of pressure on the ice XII to ice XIV phase transition

Water ice displays a remarkably complex phase diagram containing pairs of hydrogen-ordered / disordered phases. Ice XII is a hydrogen-disordered phase and ice XIV is its hydrogen-ordered counterpart, which was discovered by our group. A recent article has claimed that ice XIV can be fully hydrogen-ordered. However, this claim turned out to be the result of an integration error. In fact, only 60% ordering has been achieved so far. Following this, we have systematically explored the effect pressure has on the formation of ice XIV using in-situ pressure neutron diffraction. This has shown some remarkably complex and unexpected behaviour for deuterated ice. However, to really finish the ice XIV story, we now need to measure the corresponding protiated samples with neutron diffraction.