Garnet-type Mn3Cr2(GeO4)3

摘要

Single crystals of garnet-type trimanganese(II) dichrom­i­um(III) tris­[orthogermanate(IV)], Mn^II 3Cr^III 2(GeO4)3, were obtained by utilizing a chemical transport reaction. Corres­ponding to the mineral garnet with the general formula A ^II 3 B ^III 2(SiO4)3, each of the four elements occupies only one crystallographically distinct position. Mn²⁺ occupies the respective A position (Wyckoff site 24c, site symmetry 2.22), being surrounded by eight O atoms that form a distorted cube [d(Mn—O) = 2.291 (2) and 2.422 (2) Å, 4× each], while Cr³⁺ on the B position (Wyckoff site 16a, site symmetry .-3.) is situated in a slightly distorted octa­hedron of six O²⁻ anions [d(Cr—O) = 1.972 (2) Å, 6×]. In addition, the O atoms on general site 96h form isolated [GeO4]⁴⁻ tetra­hedra with Ge⁴⁺ on site 24d [site symmetry -4..; d(Ge—O) = 1.744 (2) Å, 4×].