https://dictionary.iucr.org/index.php?action=history&feed=atom&title=Talk%3ANoncrystallographic_symmetryTalk:Noncrystallographic symmetry - Revision history2026-06-04T05:31:31ZRevision history for this page on the wikiMediaWiki 1.30.0https://dictionary.iucr.org/index.php?title=Talk:Noncrystallographic_symmetry&diff=2743&oldid=prevMassimoNespolo at 10:19, 8 April 20082008-04-08T10:19:32Z<p></p>
<p><b>New page</b></p><div>I wonder whether there is an official position of the nomenclature commission on this expression. "Noncrystallgraphic symmetry" to me is a symmetry that does not respect the restrictions imposed by the periodicity (in whatever space). For symmetry (or pseudo-symmetry, which does not change the essence) acting on a subspace of the crystal space (thus relating subunits) the term '''partial symmetry''' is used. A special case of partial symmetry is '''local symmetry'''. The corresponding operations are space groupoid operations. They cannot be called "noncrystallographic".<br />
In the ActaA celebration issued of the 60th anniversary of IUCr and Acta, published in January 2008, I have written a short review on this topic. I urge the Nomeclature Commission to take an official position on this point. --[[User:MassimoNespolo|MassimoNespolo]] 11:19, 8 April 2008 (BST)</div>MassimoNespolo