MgCo2(SbO3)4 crystallizes in the monoclinic P2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(5) atoms. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with four equivalent Sb(4)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, and  an edgeedge with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form CoO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, and  an edgeedge with one Sb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with four equivalent Co(2)O6 octahedra, corners with four equivalent Sb(4)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with four equivalent Co(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. In the third Sb site, Sb(3) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. In the fourth Sb site, Sb(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form SbO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and  an edgeedge with one Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Co(2), one Sb(2), and one Sb(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Co(1), one Sb(3), and one Sb(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Sb(1), and one Sb(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(2), one Sb(1), and one Sb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Co(1), one Sb(2), and one Sb(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Co(2), one Sb(1), and one Sb(2) atom.
MgCo2(SbO3)4 crystallizes in the monoclinic P2 space group. Mg(1) is bonded in a 4-coordinate geometry to two equivalent O(1) and two equivalent O(5) atoms. Both Mg(1)-O(1) bond lengths are 1.92 Å. Both Mg(1)-O(5) bond lengths are 1.94 Å. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form CoO6 octahedra that share corners with four equivalent Sb(4)O6 octahedra,  an edgeedge with one Sb(1)O6 octahedra, and  an edgeedge with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. Both Co(1)-O(2) bond lengths are 2.18 Å. Both Co(1)-O(3) bond lengths are 2.21 Å. Both Co(1)-O(5) bond lengths are 2.18 Å. In the second Co site, Co(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form CoO6 octahedra that share corners with four equivalent Sb(1)O6 octahedra, corners with four equivalent Sb(2)O6 octahedra, and  an edgeedge with one Sb(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. Both Co(2)-O(1) bond lengths are 2.11 Å. Both Co(2)-O(4) bond lengths are 2.11 Å. Both Co(2)-O(6) bond lengths are 2.23 Å. There are four inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with four equivalent Co(2)O6 octahedra, corners with four equivalent Sb(4)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Sb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-48°. Both Sb(1)-O(3) bond lengths are 2.01 Å. Both Sb(1)-O(4) bond lengths are 2.11 Å. Both Sb(1)-O(6) bond lengths are 2.06 Å. In the second Sb site, Sb(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(6) atoms to form SbO6 octahedra that share corners with four equivalent Co(2)O6 octahedra,  an edgeedge with one Co(1)O6 octahedra, and  an edgeedge with one Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-52°. Both Sb(2)-O(1) bond lengths are 2.00 Å. Both Sb(2)-O(5) bond lengths are 2.12 Å. Both Sb(2)-O(6) bond lengths are 2.03 Å. In the third Sb site, Sb(3) is bonded in a 6-coordinate geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(5) atoms. Both Sb(3)-O(1) bond lengths are 2.59 Å. Both Sb(3)-O(2) bond lengths are 2.04 Å. Both Sb(3)-O(5) bond lengths are 2.32 Å. In the fourth Sb site, Sb(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form SbO6 octahedra that share corners with four equivalent Co(1)O6 octahedra, corners with four equivalent Sb(1)O6 octahedra, and  an edgeedge with one Co(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-48°. Both Sb(4)-O(2) bond lengths are 2.03 Å. Both Sb(4)-O(3) bond lengths are 2.15 Å. Both Sb(4)-O(4) bond lengths are 1.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Co(2), one Sb(2), and one Sb(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Co(1), one Sb(3), and one Sb(4) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Sb(1), and one Sb(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(2), one Sb(1), and one Sb(4) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Co(1), one Sb(2), and one Sb(3) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Co(2), one Sb(1), and one Sb(2) atom.