Ice IX

This redirect is about a real form of solid water. For the fictional material called Ice-nine that appears in the Kurt Vonnegut novel, see Cat's Cradle.

For other uses, see Ice-nine (disambiguation).

Ice IX is a form of solid water stable at temperatures below 140 K and pressures between 200 and 400 MPa. It has a tetragonal crystal lattice and a density of 1.16 g/cm³, 26% higher than ordinary ice. It is formed by cooling ice III from 208 K to 165 K (rapidly—to avoid forming ice II). Its structure is identical to ice III other than being hydrogen-ordered.

Ordinary water ice is known as ice I_h in the Bridgman nomenclature. Different types of ice, from ice II to ice XVIII, have been created in the laboratory at different temperatures and pressures.

See also

• Ice, for other crystalline forms of ice.

References

• Bridgman, P. W. (1937) J. Chem. Phys. 5, 964.
• Chaplin, Martin (2007-11-11). "Ice-three and ice-nine structures". Water Structure and Science. Retrieved 2008-01-02.

External links

• London South Bank University Report