MgV2(CO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share  an edgeedge with one V(2)O6 octahedra and edges with two equivalent V(1)O6 octahedra. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form VO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra. In the second V site, V(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form VO6 octahedra that share  an edgeedge with one Mg(1)O6 octahedra. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(6) atom. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one C(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one V(2) and one C(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one C(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one V(2), and one C(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one V(2) and one C(1) atom.
MgV2(CO3)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 octahedra that share  an edgeedge with one V(2)O6 octahedra and edges with two equivalent V(1)O6 octahedra. Both Mg(1)-O(1) bond lengths are 2.21 Å. Both Mg(1)-O(4) bond lengths are 2.16 Å. Both Mg(1)-O(5) bond lengths are 2.21 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form VO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra. Both V(1)-O(1) bond lengths are 2.07 Å. Both V(1)-O(3) bond lengths are 1.98 Å. Both V(1)-O(4) bond lengths are 2.16 Å. In the second V site, V(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms to form VO6 octahedra that share  an edgeedge with one Mg(1)O6 octahedra. Both V(2)-O(2) bond lengths are 2.00 Å. Both V(2)-O(5) bond lengths are 2.09 Å. Both V(2)-O(6) bond lengths are 1.98 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one O(3), one O(4), and one O(6) atom. The C(1)-O(3) bond length is 1.28 Å. The C(1)-O(4) bond length is 1.32 Å. The C(1)-O(6) bond length is 1.28 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one O(1), one O(2), and one O(5) atom. The C(2)-O(1) bond length is 1.32 Å. The C(2)-O(2) bond length is 1.27 Å. The C(2)-O(5) bond length is 1.30 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one C(2) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one V(2) and one C(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one V(1) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Mg(1), one V(1), and one C(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one V(2), and one C(2) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one V(2) and one C(1) atom.