DOE OSTI2020
SrCuO2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Sr2+ is bonded to seven O2- atoms to form a mixture of distorted edge, face, and corner-sharing SrO7 pentagonal bipyramids. There are a spread of Sr–O bond distances ranging from 2.49–2.70 Å. Cu2+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.91 Å) and two longer (1.99 Å) Cu–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded to five equivalent Sr2+ and one Cu2+ atom to form distorted OSr5Cu octahedra that share corners with four equivalent OSr5Cu octahedra, corners with seven equivalent OSr2Cu3 trigonal bipyramids, edges with eight equivalent OSr5Cu octahedra, and faces with two equivalent OSr2Cu3 trigonal bipyramids. The corner-sharing octahedral tilt angles are 8°. In the second O2- site, O2- is bonded to two equivalent Sr2+ and three equivalent Cu2+ atoms to form OSr2Cu3 trigonal bipyramids that share corners with seven equivalent OSr5Cu octahedra, corners with four equivalent OSr2Cu3 trigonal bipyramids, edges with two equivalent OSr2Cu3 trigonal bipyramids, and faces with two equivalent OSr5Cu octahedra. The corner-sharing octahedra tilt angles range from 0–58°.