Co3O4 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(4)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. In the third Co site, Co(3) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing CoO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-59°. In the fourth Co site, Co(4) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(3), and two equivalent Co(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(3), and one Co(4) atom. In the third O site, O(3) is bonded to one Co(3), one Co(4), and two equivalent Co(2) atoms to form distorted corner-sharing OCo4 trigonal pyramids.
Co3O4 is Spinel-derived structured and crystallizes in the monoclinic C2/m space group. There are four inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(4)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. Both Co(1)-O(1) bond lengths are 1.97 Å. All Co(1)-O(2) bond lengths are 2.03 Å. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, edges with two equivalent Co(2)O6 octahedra, and edges with two equivalent Co(4)O6 octahedra. Both Co(2)-O(1) bond lengths are 2.02 Å. Both Co(2)-O(2) bond lengths are 2.05 Å. Both Co(2)-O(3) bond lengths are 2.03 Å. In the third Co site, Co(3) is bonded to one O(1), one O(3), and two equivalent O(2) atoms to form corner-sharing CoO4 tetrahedra. The corner-sharing octahedral tilt angles range from 56-59°. The Co(3)-O(1) bond length is 1.93 Å. The Co(3)-O(3) bond length is 1.96 Å. Both Co(3)-O(2) bond lengths are 1.95 Å. In the fourth Co site, Co(4) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form CoO6 octahedra that share corners with six equivalent Co(3)O4 tetrahedra, edges with two equivalent Co(1)O6 octahedra, and edges with four equivalent Co(2)O6 octahedra. Both Co(4)-O(3) bond lengths are 1.96 Å. All Co(4)-O(2) bond lengths are 1.95 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(3), and two equivalent Co(2) atoms. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Co(1), one Co(2), one Co(3), and one Co(4) atom. In the third O site, O(3) is bonded to one Co(3), one Co(4), and two equivalent Co(2) atoms to form distorted corner-sharing OCo4 trigonal pyramids.