The melting curve
for ice-ten has been proposed at high temperatures
(1000-2400 K) [612a]. As ice X is approached with increasing pressure from very hot liquid water and the O-H energy minima draw near to each other, the protons rapidly swap positions giving many short-lived OH- and H3O+ ions [612b]. In the ice X, however, protons are less mobile than in ice VII as there is only one energy minimum for each O-H-O bond,
Ice-ten looks identical as seen from
the x, y or z direction.
Ice-ten has triple points with ice-seven
and ice-eight (100 K, 62 GPa) and ice-seven and water
(~1000 K, ~47 GPa) [612b].
Interactive Jmol structures are given.