YBaCo4O7 crystallizes in the orthorhombic Cmc2_1 space group. Ba(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, edges with three equivalent Co(1)O4 tetrahedra, edges with three equivalent Co(3)O4 tetrahedra, edges with six equivalent Co(2)O4 tetrahedra, and faces with four equivalent Y(1)O6 octahedra. Y(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form YO6 octahedra that share corners with three equivalent Co(1)O4 tetrahedra, corners with three equivalent Co(3)O4 tetrahedra, corners with six equivalent Co(2)O4 tetrahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with four equivalent Co(2)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 54-58°. In the second Co site, Co(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Co(3)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 55-58°. In the third Co site, Co(3) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Co(2)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Co(1), and one Co(3) atom. In the second O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Y(1), one Co(2), and one Co(3) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), and two equivalent Co(2) atoms. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Co(1), and one Co(2) atom. In the fifth O site, O(3) is bonded in a tetrahedral geometry to one Co(1), one Co(3), and two equivalent Co(2) atoms.
YBaCo4O7 crystallizes in the orthorhombic Cmc2_1 space group. Ba(1) is bonded to two equivalent O(1), two equivalent O(4), four equivalent O(2), and four equivalent O(5) atoms to form BaO12 cuboctahedra that share corners with twelve equivalent Ba(1)O12 cuboctahedra, edges with three equivalent Co(1)O4 tetrahedra, edges with three equivalent Co(3)O4 tetrahedra, edges with six equivalent Co(2)O4 tetrahedra, and faces with four equivalent Y(1)O6 octahedra. There is one shorter (3.13 Å) and one longer (3.19 Å) Ba(1)-O(1) bond length. Both Ba(1)-O(4) bond lengths are 3.23 Å. There are two shorter (3.16 Å) and two longer (3.22 Å) Ba(1)-O(2) bond lengths. There are two shorter (3.13 Å) and two longer (3.30 Å) Ba(1)-O(5) bond lengths. Y(1) is bonded to one O(1), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form YO6 octahedra that share corners with three equivalent Co(1)O4 tetrahedra, corners with three equivalent Co(3)O4 tetrahedra, corners with six equivalent Co(2)O4 tetrahedra, and faces with four equivalent Ba(1)O12 cuboctahedra. The Y(1)-O(1) bond length is 2.25 Å. The Y(1)-O(4) bond length is 2.30 Å. Both Y(1)-O(2) bond lengths are 2.24 Å. Both Y(1)-O(5) bond lengths are 2.33 Å. There are three inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(3)O4 tetrahedra, corners with four equivalent Co(2)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 54-58°. The Co(1)-O(3) bond length is 2.00 Å. The Co(1)-O(4) bond length is 1.97 Å. Both Co(1)-O(2) bond lengths are 1.95 Å. In the second Co site, Co(2) is bonded to one O(1), one O(2), one O(3), and one O(5) atom to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with two equivalent Co(2)O4 tetrahedra, corners with two equivalent Co(3)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 55-58°. The Co(2)-O(1) bond length is 1.95 Å. The Co(2)-O(2) bond length is 1.94 Å. The Co(2)-O(3) bond length is 2.01 Å. The Co(2)-O(5) bond length is 2.00 Å. In the third Co site, Co(3) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form CoO4 tetrahedra that share corners with three equivalent Y(1)O6 octahedra, corners with two equivalent Co(1)O4 tetrahedra, corners with four equivalent Co(2)O4 tetrahedra, and edges with three equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 50-51°. The Co(3)-O(3) bond length is 1.95 Å. The Co(3)-O(4) bond length is 1.90 Å. Both Co(3)-O(5) bond lengths are 1.86 Å. There are five inequivalent O sites. In the first O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Co(1), and one Co(3) atom. In the second O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ba(1), one Y(1), one Co(2), and one Co(3) atom. In the third O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), and two equivalent Co(2) atoms. In the fourth O site, O(2) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1), one Y(1), one Co(1), and one Co(2) atom. In the fifth O site, O(3) is bonded in a tetrahedral geometry to one Co(1), one Co(3), and two equivalent Co(2) atoms.