Materials Data on BaYCoCuO5 by Materials Project
YBaCuCoO5 crystallizes in the tetragonal P4/nmm space group. The structure is three-dimensional. Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent BaO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, faces with four equivalent CuO5 square pyramids, and faces with four equivalent CoO5 trigonal bipyramids. There are four shorter (2.76 Å) and eight longer (3.09 Å) Ba–O bond lengths. Y3+ is bonded in a body-centered cubic geometry to eight equivalent O2- atoms. All Y–O bond lengths are 2.41 Å. Co3+ is bonded to five O2- atoms to form distorted CoO5 trigonal bipyramids that share corners with five equivalent CuO5 square pyramids and faces with four equivalent BaO12 cuboctahedra. There is one shorter (1.80 Å) and four longer (1.99 Å) Co–O bond length. Cu2+ is bonded to five O2- atoms to form CuO5 square pyramids that share corners with five equivalent CoO5 trigonal bipyramids and faces with four equivalent BaO12 cuboctahedra. There are four shorter (1.98 Å) and one longer (2.31 Å) Cu–O bond lengths. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two equivalent Ba2+, two equivalent Y3+, one Co3+, and one Cu2+ atom. In the second O2- site, O2- is bonded to four equivalent Ba2+, one Co3+, and one Cu2+ atom to form a mixture of distorted corner and edge-sharing OBa4CoCu octahedra. The corner-sharing octahedral tilt angles are 5°.