Abstract
ZnIn2Se4 crystallizes in the tetragonal space group I[unk]2m, with lattice parameters a = 5.7095(7) and c = 11.449(2) Å. The structure was solved with 361 independent observed reflections and refined to R = 0.021. The resulting positional parameters of Se at the special site xxz (8i) are x = 0.2302(1) and z = 0.3841(1). Zn and In are randomly distributed on the special sites O[unk] (4d) and 000 (2a) in their molar ratio 1:2, the vacancies are located at the special site 00[unk] (2b). The metals are tetrahedrally coordinated by selenium. For the metals at (2a) the tetrahedra are compressed, whereas those for the metals at (4d) are elongated along c, indicating a displacement of the Se atoms towards neighbouring vacancies. The structure is related to the defect-zincblende structure by vancancy ordering and to the defect-chalcopyrite (thiogallate) structure by cation disordering; it is isotypic to MgIn2Te4 and MnIn2Te4.
