Materials Data on KBa3Y2(Co3O8)2 by Materials Project

Abstract

KBa3Y2(Co3O8)2 crystallizes in the tetragonal I4mm space group. The structure is three-dimensional. K1+ is bonded to twelve O2- atoms to form KO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with four equivalent BaO12 cuboctahedra, faces with five BaO12 cuboctahedra, faces with four equivalent CoO6 octahedra, and faces with four equivalent CoO5 trigonal bipyramids. There are eight shorter (2.79 Å) and four longer (3.12 Å) K–O bond lengths. There are three inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with eight BaO12 cuboctahedra, a faceface with one BaO12 cuboctahedra, faces with four equivalent KO12 cuboctahedra, faces with four equivalent CoO6 octahedra, and faces with four equivalent CoO5 trigonal bipyramids. There are a spread of Ba–O bond distances ranging from 2.76–3.10 Å. In the second Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with four equivalent KO12 cuboctahedra, corners with four equivalent BaO12 cuboctahedra, faces with five BaO12 cuboctahedra, faces with four equivalent CoO6 octahedra, and faces with four equivalent CoO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.75–3.08 Å. In the third Ba2+ site, Ba2+ is bonded to twelve O2- atoms to form BaO12 cuboctahedra that share corners with eight BaO12 cuboctahedra, a faceface with one KO12 cuboctahedra, faces with four equivalent BaO12 cuboctahedra, faces with four equivalent CoO6 octahedra, and faces with four equivalent CoO5 square pyramids. There are a spread of Ba–O bond distances ranging from 2.75–3.13 Å. There are two inequivalent Y3+ sites. In the first Y3+ site, Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.40 Å) and four longer (2.45 Å) Y–O bond lengths. In the second Y3+ site, Y3+ is bonded in a body-centered cubic geometry to eight O2- atoms. There are four shorter (2.40 Å) and four longer (2.47 Å) Y–O bond lengths. There are three inequivalent Co+3.17+ sites. In the first Co+3.17+ site, Co+3.17+ is bonded to five O2- atoms to form distorted CoO5 trigonal bipyramids that share a cornercorner with one CoO6 octahedra, corners with four equivalent CoO5 trigonal bipyramids, faces with two equivalent KO12 cuboctahedra, and faces with two equivalent BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are one shorter (1.98 Å) and four longer (2.03 Å) Co–O bond lengths. In the second Co+3.17+ site, Co+3.17+ is bonded to five O2- atoms to form CoO5 square pyramids that share a cornercorner with one CoO6 octahedra, corners with four equivalent CoO5 square pyramids, and faces with four BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.01 Å) and one longer (2.08 Å) Co–O bond lengths. In the third Co+3.17+ site, Co+3.17+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with four equivalent CoO6 octahedra, a cornercorner with one CoO5 square pyramid, a cornercorner with one CoO5 trigonal bipyramid, faces with two equivalent KO12 cuboctahedra, and faces with six BaO12 cuboctahedra. The corner-sharing octahedral tilt angles are 3°. There are a spread of Co–O bond distances ranging from 1.85–1.97 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 4-coordinate geometry to two Ba2+, two Y3+, and two equivalent Co+3.17+ atoms. In the second O2- site, O2- is bonded in a distorted linear geometry to one K1+, three Ba2+, and two equivalent Co+3.17+ atoms. In the third O2- site, O2- is bonded in a distorted linear geometry to two equivalent K1+, two equivalent Ba2+, and two Co+3.17+ atoms. In the fourth O2- site, O2- is bonded to four Ba2+ and two Co+3.17+ atoms to form a mixture of distorted edge and corner-sharing OBa4Co2 octahedra. The corner-sharing octahedra tilt angles range from 1–3°. In the fifth O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, one Ba2+, two Y3+, and two equivalent Co+3.17+ atoms.