ZnCo2O4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form distorted CoO6 octahedra that share corners with two equivalent Zn(1)O5 square pyramids, edges with four equivalent Co(1)O6 octahedra, and edges with three equivalent Zn(1)O5 square pyramids. In the second Co site, Co(2) is bonded in a 6-coordinate geometry to one O(1), two equivalent O(2), and three equivalent O(4) atoms. Zn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form ZnO5 square pyramids that share corners with two equivalent Co(1)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, and edges with two equivalent Zn(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 10°. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Co(2), two equivalent Co(1), and one Zn(1) atom to form OZnCo3 trigonal pyramids that share corners with two equivalent O(3)Zn2Co3 square pyramids, corners with two equivalent O(1)ZnCo3 trigonal pyramids, and edges with three equivalent O(3)Zn2Co3 square pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Co(1) and two equivalent Co(2) atoms. In the third O site, O(3) is bonded to three equivalent Co(1) and two equivalent Zn(1) atoms to form OZn2Co3 square pyramids that share corners with two equivalent O(1)ZnCo3 trigonal pyramids, edges with four equivalent O(3)Zn2Co3 square pyramids, and edges with three equivalent O(1)ZnCo3 trigonal pyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Co(2) and two equivalent Zn(1) atoms.
ZnCo2O4 crystallizes in the monoclinic C2/m space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), two equivalent O(1), and three equivalent O(3) atoms to form distorted CoO6 octahedra that share corners with two equivalent Zn(1)O5 square pyramids, edges with four equivalent Co(1)O6 octahedra, and edges with three equivalent Zn(1)O5 square pyramids. The Co(1)-O(2) bond length is 1.88 Å. Both Co(1)-O(1) bond lengths are 1.99 Å. There are two shorter (2.10 Å) and one longer (2.32 Å) Co(1)-O(3) bond length. In the second Co site, Co(2) is bonded in a 6-coordinate geometry to one O(1), two equivalent O(2), and three equivalent O(4) atoms. The Co(2)-O(1) bond length is 1.93 Å. Both Co(2)-O(2) bond lengths are 1.93 Å. There is one shorter (1.87 Å) and two longer (2.49 Å) Co(2)-O(4) bond lengths. Zn(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form ZnO5 square pyramids that share corners with two equivalent Co(1)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, and edges with two equivalent Zn(1)O5 square pyramids. The corner-sharing octahedral tilt angles are 10°. The Zn(1)-O(1) bond length is 2.10 Å. Both Zn(1)-O(3) bond lengths are 2.09 Å. Both Zn(1)-O(4) bond lengths are 2.05 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Co(2), two equivalent Co(1), and one Zn(1) atom to form OZnCo3 trigonal pyramids that share corners with two equivalent O(3)Zn2Co3 square pyramids, corners with two equivalent O(1)ZnCo3 trigonal pyramids, and edges with three equivalent O(3)Zn2Co3 square pyramids. In the second O site, O(2) is bonded in a trigonal planar geometry to one Co(1) and two equivalent Co(2) atoms. In the third O site, O(3) is bonded to three equivalent Co(1) and two equivalent Zn(1) atoms to form OZn2Co3 square pyramids that share corners with two equivalent O(1)ZnCo3 trigonal pyramids, edges with four equivalent O(3)Zn2Co3 square pyramids, and edges with three equivalent O(1)ZnCo3 trigonal pyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to three equivalent Co(2) and two equivalent Zn(1) atoms.