Crystallography365

Blogging a crystal structure a day in 2014

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Helen Maynard-Casely

Stranger than fiction – Ice IX

What does it look like?

Image generated by the VESTA (Visualisation for Electronic and STructual analysis) software http://jp-minerals.org/vesta/en/

Image generated by the VESTA (Visualisation for Electronic and STructual analysis) software http://jp-minerals.org/vesta/en/

What is it?

In Kurt Vonnegut's 1963 book Cat’s Cradle, he writes of a structure of ice known as Ice IX. In the book this form of ice works as a seed crystal, and will solidify any other water it comes in contact with.

Ice IX does exist, but is a form of ice that can only stabilise at relatively high pressures and low temperatures. In this case fiction is stranger than fact, as ice IX would not stay solid without those conditions. It's an ordered form of ice, which means that unlike its polymorph ice Ih, the water molecules in ice IX are pretty much stationary and do not flip about.

Where did the structure come from?

The structure and ordering of Ice IX was investigated by La Placa et al.  in 1973.

Tags: ice IX   ice   neutrons