Beschreibung:
AbstractThe structural relations of La2Sb type compounds and their oxygen stuffed variants, like e.g. Eu4Sb2O (anti‐K2NiF4 type), are discussed. In the course of these investigations, the crystal structures of La2Sb, Pr2Sb, Sm2Sb, Nd2Bi, and Sm4Bi2O were determined and refined from single crystal data. Band structures have been calculated in the framework of density functional theory, and the bonding properties of the individual compounds are compared on the basis of the Electron Localization Function (ELF). Based on specific geometrical parameters, the La2Sb type compounds are arranged in a structure field map. Three distinct areas arise: insulating K2NiF4 type compounds, semiconducting, oxygen stuffed variants and oxygen‐free metallic compounds. La2Sb is found in the latter area, ruling out oxygen content, which is confirmed by high resolution single‐crystal X‐ray diffraction. The electronic structures of the compounds are related to the valence electron count. Pnictides of tri‐valent metals are metallic and feature local multicenter metal–metal bonds, di‐valent metals form oxygen stuffed variants. Samarium is the only element which is found in both areas of the structure field map, displaying an oxygen free and a stuffed variant.