Materials Data on SrCuBiO4 by Materials Project
SrCuBiO4 crystallizes in the tetragonal I4/mmm space group. The structure is two-dimensional and consists of four SrCuBiO4 sheets oriented in the (0, 0, 1) direction. Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.52–3.01 Å. Cu1+ is bonded in a square co-planar geometry to four equivalent O2- atoms. All Cu–O bond lengths are 1.85 Å. Bi5+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing BiO5 square pyramids. There are one shorter (2.06 Å) and four longer (2.54 Å) Bi–O bond lengths. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded to one Sr2+ and four equivalent Bi5+ atoms to form OSrBi4 square pyramids that share corners with four equivalent OSrBi4 square pyramids, corners with four equivalent OSr2Cu2 trigonal pyramids, and edges with four equivalent OSrBi4 square pyramids. In the second O2- site, O2- is bonded to two equivalent Sr2+ and two equivalent Cu1+ atoms to form distorted OSr2Cu2 trigonal pyramids that share corners with two equivalent OSrBi4 square pyramids, corners with four equivalent OSr2Cu2 trigonal pyramids, and edges with four equivalent OSr2Cu2 trigonal pyramids. In the third O2- site, O2- is bonded in a 5-coordinate geometry to four equivalent Sr2+ and one Bi5+ atom.