MgAl2(CoO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CoO6 octahedra that share corners with three equivalent Al(2)O6 octahedra, edges with three equivalent Al(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-42°. In the second Co site, Co(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form AlO6 octahedra that share corners with three equivalent Al(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 38°. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form AlO6 octahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Al(1)O6 octahedra,  a faceface with one Co(1)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-42°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids.
MgAl2(CoO3)2 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Mg(1)-O(1) bond length is 2.00 Å. The Mg(1)-O(2) bond length is 2.26 Å. The Mg(1)-O(3) bond length is 2.00 Å. The Mg(1)-O(4) bond length is 2.27 Å. The Mg(1)-O(5) bond length is 2.01 Å. The Mg(1)-O(6) bond length is 2.26 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted CoO6 octahedra that share corners with three equivalent Al(2)O6 octahedra, edges with three equivalent Al(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-42°. The Co(1)-O(1) bond length is 2.06 Å. The Co(1)-O(2) bond length is 2.17 Å. The Co(1)-O(3) bond length is 2.03 Å. The Co(1)-O(4) bond length is 2.18 Å. The Co(1)-O(5) bond length is 2.02 Å. The Co(1)-O(6) bond length is 2.20 Å. In the second Co site, Co(2) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Co(2)-O(1) bond length is 2.41 Å. The Co(2)-O(2) bond length is 2.04 Å. The Co(2)-O(3) bond length is 2.42 Å. The Co(2)-O(4) bond length is 2.04 Å. The Co(2)-O(5) bond length is 2.41 Å. The Co(2)-O(6) bond length is 2.04 Å. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form AlO6 octahedra that share corners with three equivalent Al(2)O6 octahedra, edges with three equivalent Co(1)O6 octahedra, and  a faceface with one Al(2)O6 octahedra. The corner-sharing octahedral tilt angles are 38°. The Al(1)-O(1) bond length is 1.99 Å. The Al(1)-O(2) bond length is 1.95 Å. The Al(1)-O(3) bond length is 1.99 Å. The Al(1)-O(4) bond length is 1.94 Å. The Al(1)-O(5) bond length is 1.98 Å. The Al(1)-O(6) bond length is 1.94 Å. In the second Al site, Al(2) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form AlO6 octahedra that share corners with three equivalent Co(1)O6 octahedra, corners with three equivalent Al(1)O6 octahedra,  a faceface with one Co(1)O6 octahedra, and  a faceface with one Al(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 38-42°. The Al(2)-O(1) bond length is 1.92 Å. The Al(2)-O(2) bond length is 1.95 Å. The Al(2)-O(3) bond length is 1.92 Å. The Al(2)-O(4) bond length is 1.95 Å. The Al(2)-O(5) bond length is 1.93 Å. The Al(2)-O(6) bond length is 1.95 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the second O site, O(2) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), one Co(1), one Co(2), one Al(1), and one Al(2) atom to form a mixture of distorted corner and edge-sharing OMgAl2Co2 trigonal bipyramids.