Lanthanum tetrazinc,LaZn4

The structure of lanthanum tetrazinc, LaZn₄, has been determined from single‐crystal X‐ray diffraction data for the first time, approximately 70 years after its discovery. The compound exhibits a new structure type in the space group Cmcm, with one La atom and two Zn atoms occupying sites with m2m symmetry, and one Zn atom occupying a site with 2.. symmetry. The structure is closely related to the BaAl₄, La₃Al₁₁, BaNi₂Si₂ and CaCu₅ structure types, which can be presented as close‐packed arrangements of 18‐vertex clusters, in this case LaZn₁₈. The kindred structure types contain related 18‐vertex clusters around atoms of the rare earth or alkaline earth metal.