Materials Data on BaCuO2 by Materials Project

Abstract

BaCuO2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ba2+ is bonded to seven O2- atoms to form a mixture of distorted corner, edge, and face-sharing BaO7 pentagonal bipyramids. There are a spread of Ba–O bond distances ranging from 2.67–2.88 Å. Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There are a spread of Cu–O bond distances ranging from 1.89–2.05 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five equivalent Ba2+ and one Cu2+ atom to form distorted OBa5Cu octahedra that share corners with four equivalent OBa5Cu octahedra, corners with seven equivalent OBa2Cu3 trigonal bipyramids, edges with eight equivalent OBa5Cu octahedra, and faces with two equivalent OBa2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°. In the second O2- site, O2- is bonded to two equivalent Ba2+ and three equivalent Cu2+ atoms to form distorted OBa2Cu3 trigonal bipyramids that share corners with seven equivalent OBa5Cu octahedra, corners with four equivalent OBa2Cu3 trigonal bipyramids, edges with two equivalent OBa2Cu3 trigonal bipyramids, and faces with two equivalent OBa5Cu octahedra. The corner-sharing octahedra tilt angles range from 0–56°.