MgCo2O5 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Co(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing CoO5 trigonal bipyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and two equivalent Co(1) atoms to form OMg2Co2 tetrahedra that share corners with two equivalent O(1)Mg2Co2 tetrahedra, corners with two equivalent O(2)MgCo3 trigonal pyramids, and edges with four equivalent O(2)MgCo3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted OMgCo3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Co2 tetrahedra, corners with three equivalent O(2)MgCo3 trigonal pyramids, edges with two equivalent O(1)Mg2Co2 tetrahedra, and edges with two equivalent O(2)MgCo3 trigonal pyramids. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Co(1) atom.
MgCo2O5 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Mg(1)-O(1) bond lengths are 2.05 Å. Both Mg(1)-O(2) bond lengths are 2.27 Å. Both Mg(1)-O(3) bond lengths are 2.06 Å. Co(1) is bonded to one O(1), one O(3), and three equivalent O(2) atoms to form a mixture of distorted corner and edge-sharing CoO5 trigonal bipyramids. The Co(1)-O(1) bond length is 1.98 Å. The Co(1)-O(3) bond length is 1.70 Å. There are two shorter (1.97 Å) and one longer (1.99 Å) Co(1)-O(2) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and two equivalent Co(1) atoms to form OMg2Co2 tetrahedra that share corners with two equivalent O(1)Mg2Co2 tetrahedra, corners with two equivalent O(2)MgCo3 trigonal pyramids, and edges with four equivalent O(2)MgCo3 trigonal pyramids. In the second O site, O(2) is bonded to one Mg(1) and three equivalent Co(1) atoms to form distorted OMgCo3 trigonal pyramids that share  a cornercorner with one O(1)Mg2Co2 tetrahedra, corners with three equivalent O(2)MgCo3 trigonal pyramids, edges with two equivalent O(1)Mg2Co2 tetrahedra, and edges with two equivalent O(2)MgCo3 trigonal pyramids. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Mg(1) and one Co(1) atom.