Materials Data on Sr2GdCr(CuO4)2 by Materials Project

Abstract

Sr2GdCr(CuO4)2 crystallizes in the orthorhombic Amm2 space group. The structure is three-dimensional. Sr2+ is bonded to twelve O2- atoms to form SrO12 cuboctahedra that share corners with eight equivalent SrO12 cuboctahedra, faces with five equivalent SrO12 cuboctahedra, faces with four equivalent CrO6 octahedra, and faces with four equivalent CuO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.70–3.09 Å. Gd3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Gd–O bond lengths are 2.42 Å. Cr6+ is bonded to six O2- atoms to form CrO6 octahedra that share corners with four equivalent CrO6 octahedra, corners with two equivalent CuO5 square pyramids, and faces with eight equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There is four shorter (1.92 Å) and two longer (1.93 Å) Cr–O bond length. Cu+1.50+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one CrO6 octahedra, corners with four equivalent CuO5 square pyramids, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (1.96 Å) and one longer (2.04 Å) Cu–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Sr2+, two equivalent Gd3+, and two equivalent Cu+1.50+ atoms. In the second O2- site, O2- is bonded to four equivalent Sr2+, one Cr6+, and one Cu+1.50+ atom to form a mixture of distorted corner and edge-sharing OSr4CrCu octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the third O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Cr6+ atoms.