Ice VI
Ice VI is a form of ice that exists at high pressure at the order of about 1 GPa and temperatures ranging from 130 up to 355 Kelvin ; see also the phase diagram of water. Its discovery and the discovery of other high pressure forms of water was published by P.W. Bridgman in January 1912.Properties
Ice VI has a density of 1.31 g/cm³ and a tetragonal crystal system with the space group P42/nmc; its unit cell contains 10 water molecules and has the dimensions a=6.27 Å and c=5.79 Å.
The triple point of ice VI with ice VII and liquid water is at about 82°C and 2.22 GPa and its triple point with ice V and liquid water is at 0.16°C and 0.6324 GPa = 6324 bar.
