Y2Co2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. In the second Y site, Y(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form YO12 cuboctahedra that share corners with four equivalent Y(2)O12 cuboctahedra, faces with four equivalent Y(2)O12 cuboctahedra, and faces with eight equivalent Co(1)O5 square pyramids. Co(1) is bonded to one O(2) and four equivalent O(1) atoms to form CoO5 square pyramids that share corners with five equivalent Co(1)O5 square pyramids and faces with four equivalent Y(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1), two equivalent Y(2), and two equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing OY4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-67°. In the second O site, O(2) is bonded to four equivalent Y(2) and two equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing OY4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°.
Y2Co2O5 crystallizes in the tetragonal P4/mmm space group. There are two inequivalent Y sites. In the first Y site, Y(1) is bonded in a body-centered cubic geometry to eight equivalent O(1) atoms. All Y(1)-O(1) bond lengths are 2.42 Å. In the second Y site, Y(2) is bonded to four equivalent O(2) and eight equivalent O(1) atoms to form YO12 cuboctahedra that share corners with four equivalent Y(2)O12 cuboctahedra, faces with four equivalent Y(2)O12 cuboctahedra, and faces with eight equivalent Co(1)O5 square pyramids. All Y(2)-O(2) bond lengths are 2.67 Å. All Y(2)-O(1) bond lengths are 2.65 Å. Co(1) is bonded to one O(2) and four equivalent O(1) atoms to form CoO5 square pyramids that share corners with five equivalent Co(1)O5 square pyramids and faces with four equivalent Y(2)O12 cuboctahedra. The Co(1)-O(2) bond length is 2.01 Å. All Co(1)-O(1) bond lengths are 1.89 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Y(1), two equivalent Y(2), and two equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing OY4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-67°. In the second O site, O(2) is bonded to four equivalent Y(2) and two equivalent Co(1) atoms to form a mixture of distorted corner, edge, and face-sharing OY4Co2 octahedra. The corner-sharing octahedral tilt angles range from 0-60°.