Angewandte Chemie Communications The nitridoberyllates of the heavier alkaline-earth metals contain anion layers with covalent Be ÀN bonds. Mg[Be 2 N 2 ] occupies a special position among this class of compounds, since, unlike the Ca, Sr, and Ba compounds, it contains puckered [BeN] layers. For more informa- tion on these structures see the Communication by R. Kniep et al. on the following pages. 1087 Angew. Chem. Int. Ed. 2004, 43, 1087 DOI: 10.1002/anie.200352796 # 2004 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim