Materials Data on Ba2Gd(CuO2)4 by Materials Project

GdBa2Cu4O8 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Ba2+ is bonded in a distorted q6 geometry to ten O2- atoms. There are four shorter (2.78 Å) and six longer (2.99 Å) Ba–O bond lengths. Gd3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.42 Å) and four longer (2.43 Å) Gd–O bond lengths. There are two inequivalent Cu+2.25+ sites. In the first Cu+2.25+ site, Cu+2.25+ is bonded to five O2- atoms to form corner-sharing CuO5 square pyramids. There are four shorter (1.97 Å) and one longer (2.29 Å) Cu–O bond lengths. In the second Cu+2.25+ site, Cu+2.25+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.84–1.96 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded to four equivalent Ba2+ and two Cu+2.25+ atoms to form a mixture of distorted edge and corner-sharing OBa4Cu2 octahedra. The corner-sharing octahedral tilt angles are 11°. In the second O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Gd3+, and two equivalent Cu+2.25+ atoms. In the third O2- site, O2- is bonded in a distorted T-shaped geometry to two equivalent Ba2+ and three equivalent Cu+2.25+ atoms. In the fourth O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Gd3+, and two equivalent Cu+2.25+ atoms.