MgZn2(CoO3)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Zn(1)O5 trigonal bipyramids, corners with four equivalent Co(1)O4 trigonal pyramids, edges with two equivalent Zn(1)O5 trigonal bipyramids, and edges with two equivalent Co(1)O4 trigonal pyramids. Co(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted CoO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with six equivalent Zn(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Co(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles are 71°. Zn(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form ZnO5 trigonal bipyramids that share corners with three equivalent Mg(1)O6 octahedra, corners with six equivalent Co(1)O4 trigonal pyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Zn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 39-60°. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Co(1), and one Zn(1) atom to form OMgZnCo2 trigonal pyramids that share  a cornercorner with one O(1)MgZnCo2 trigonal pyramid, corners with four equivalent O(3)MgZn2Co trigonal pyramids, corners with six equivalent O(2)MgZn2Co trigonal pyramids,  an edgeedge with one O(3)MgZn2Co trigonal pyramid, and  an edgeedge with one O(1)MgZnCo2 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Co(1), and two equivalent Zn(1) atoms to form distorted OMgZn2Co trigonal pyramids that share  a cornercorner with one O(2)MgZn2Co trigonal pyramid, corners with five equivalent O(3)MgZn2Co trigonal pyramids, corners with six equivalent O(1)MgZnCo2 trigonal pyramids,  an edgeedge with one O(2)MgZn2Co trigonal pyramid, and  an edgeedge with one O(3)MgZn2Co trigonal pyramid. In the third O site, O(3) is bonded to one Mg(1), one Co(1), and two equivalent Zn(1) atoms to form distorted OMgZn2Co trigonal pyramids that share  a cornercorner with one O(3)MgZn2Co trigonal pyramid, corners with four equivalent O(1)MgZnCo2 trigonal pyramids, corners with five equivalent O(2)MgZn2Co trigonal pyramids,  an edgeedge with one O(2)MgZn2Co trigonal pyramid,  an edgeedge with one O(3)MgZn2Co trigonal pyramid, and  an edgeedge with one O(1)MgZnCo2 trigonal pyramid.
MgZn2(CoO3)2 crystallizes in the triclinic P-1 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form MgO6 octahedra that share corners with six equivalent Zn(1)O5 trigonal bipyramids, corners with four equivalent Co(1)O4 trigonal pyramids, edges with two equivalent Zn(1)O5 trigonal bipyramids, and edges with two equivalent Co(1)O4 trigonal pyramids. Both Mg(1)-O(1) bond lengths are 2.14 Å. Both Mg(1)-O(2) bond lengths are 2.19 Å. Both Mg(1)-O(3) bond lengths are 2.02 Å. Co(1) is bonded to one O(2), one O(3), and two equivalent O(1) atoms to form distorted CoO4 trigonal pyramids that share corners with two equivalent Mg(1)O6 octahedra, corners with six equivalent Zn(1)O5 trigonal bipyramids,  an edgeedge with one Mg(1)O6 octahedra, and  an edgeedge with one Co(1)O4 trigonal pyramid. The corner-sharing octahedral tilt angles are 71°. The Co(1)-O(2) bond length is 1.83 Å. The Co(1)-O(3) bond length is 1.83 Å. There is one shorter (1.93 Å) and one longer (2.04 Å) Co(1)-O(1) bond length. Zn(1) is bonded to one O(1), two equivalent O(2), and two equivalent O(3) atoms to form ZnO5 trigonal bipyramids that share corners with three equivalent Mg(1)O6 octahedra, corners with six equivalent Co(1)O4 trigonal pyramids,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Zn(1)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 39-60°. The Zn(1)-O(1) bond length is 2.05 Å. There is one shorter (2.10 Å) and one longer (2.15 Å) Zn(1)-O(2) bond length. There is one shorter (2.02 Å) and one longer (2.13 Å) Zn(1)-O(3) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), two equivalent Co(1), and one Zn(1) atom to form OMgZnCo2 trigonal pyramids that share  a cornercorner with one O(1)MgZnCo2 trigonal pyramid, corners with four equivalent O(3)MgZn2Co trigonal pyramids, corners with six equivalent O(2)MgZn2Co trigonal pyramids,  an edgeedge with one O(3)MgZn2Co trigonal pyramid, and  an edgeedge with one O(1)MgZnCo2 trigonal pyramid. In the second O site, O(2) is bonded to one Mg(1), one Co(1), and two equivalent Zn(1) atoms to form distorted OMgZn2Co trigonal pyramids that share  a cornercorner with one O(2)MgZn2Co trigonal pyramid, corners with five equivalent O(3)MgZn2Co trigonal pyramids, corners with six equivalent O(1)MgZnCo2 trigonal pyramids,  an edgeedge with one O(2)MgZn2Co trigonal pyramid, and  an edgeedge with one O(3)MgZn2Co trigonal pyramid. In the third O site, O(3) is bonded to one Mg(1), one Co(1), and two equivalent Zn(1) atoms to form distorted OMgZn2Co trigonal pyramids that share  a cornercorner with one O(3)MgZn2Co trigonal pyramid, corners with four equivalent O(1)MgZnCo2 trigonal pyramids, corners with five equivalent O(2)MgZn2Co trigonal pyramids,  an edgeedge with one O(2)MgZn2Co trigonal pyramid,  an edgeedge with one O(3)MgZn2Co trigonal pyramid, and  an edgeedge with one O(1)MgZnCo2 trigonal pyramid.