Making Waves: Low-temperature CuCN has a curious wave structure (see picture Cu purple, C/N blue). Interconversion of this and the high-temperature, highly disordered form can be achieved at room-temperature via a novel zeolitic intermediate which is also structurally characterized. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2004/z52844_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.