Experimental Crystal data

R factor = 0.017; wR factor = 0.050; data-to-parameter ratio = 27.4. Barium dierbium(III) tetrasulfide, BaEr2S4, crystallizes with four formula units in the orthorhombic space group Pnma in the CaFe2O4 structure type. The asymmetric unit contains two Er, one Ba, and four S atoms, each with.m. site symmetry. The structure consists of channels formed by corner- and edge-sharing ErS6 octahedra in which Ba atoms reside. The resultant coordination of Ba is that of a bicapped trigonal prism. Related literature The unit-cell parameters of BaEr2S4, which crystallizes in the CaFe2O4 structure type (Decker & Kasper, 1957), were previously determined from X-ray powder diffraction dat