Materials Data on Sr2GdCu2IrO8 by Materials Project

Abstract

IrSr2GdCu2O8 crystallizes in the monoclinic C2 space group. The structure is three-dimensional. Sr2+ is bonded to twelve O2- atoms to form distorted SrO12 cuboctahedra that share corners with eight equivalent SrO12 cuboctahedra, faces with five equivalent SrO12 cuboctahedra, faces with four equivalent IrO6 octahedra, and faces with four equivalent CuO5 square pyramids. There are a spread of Sr–O bond distances ranging from 2.69–3.17 Å. Gd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.44 Å) and four longer (2.45 Å) Gd–O bond lengths. Ir5+ is bonded to six O2- atoms to form IrO6 octahedra that share corners with four equivalent IrO6 octahedra, corners with two equivalent CuO5 square pyramids, and faces with eight equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 8°. There are a spread of Ir–O bond distances ranging from 1.93–2.03 Å. Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share a cornercorner with one IrO6 octahedra, corners with four equivalent CuO5 square pyramids, and faces with four equivalent SrO12 cuboctahedra. The corner-sharing octahedral tilt angles are 1°. There are four shorter (1.95 Å) and one longer (2.23 Å) Cu–O bond lengths. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Gd3+, and two equivalent Cu2+ atoms. In the second O2- site, O2- is bonded in a 6-coordinate geometry to two equivalent Sr2+, two equivalent Gd3+, and two equivalent Cu2+ atoms. In the third O2- site, O2- is bonded to four equivalent Sr2+, one Ir5+, and one Cu2+ atom to form a mixture of distorted edge and corner-sharing OSr4CuIr octahedra. The corner-sharing octahedra tilt angles range from 2–12°. In the fourth O2- site, O2- is bonded in a distorted linear geometry to four equivalent Sr2+ and two equivalent Ir5+ atoms.