Icicle - entropy

Ice VII is the only disordered phase of ice that can be ordered by simple cooling, [5] [11] and it forms (ordered) ice VIII below 273 K up to ~8 GPa. Above this pressure, the VII–VIII transition temperature drops rapidly, reaching 0 K at ~60 GPa. [12] Thus, ice VII has the largest stability field of all of the molecular phases of ice. The cubic oxygen sub-lattices that form the backbone of the ice VII structure persist to pressures of at least 128 GPa; [13] this pressure is substantially higher than that at which water loses its molecular character entirely, forming ice X . In high pressure ices, protonic diffusion (movement of protons around the oxygen lattice) dominates molecular diffusion, an effect which has been measured directly. [14]

Icicle - EntropyIcicle - EntropyIcicle - EntropyIcicle - Entropy