Mg1VO2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent V(2)O6 octahedra, corners with four equivalent Mg(2)O4 tetrahedra, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent V(2)O6 octahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with four equivalent Mg(1)O5 trigonal bipyramids, and edges with three equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. There are two inequivalent V sites. In the first V site, V(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. In the second V site, V(2) is bonded to one O(1), two equivalent O(4), and three equivalent O(2) atoms to form distorted VO6 octahedra that share corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with four equivalent V(2)O6 octahedra, edges with three equivalent Mg(2)O4 tetrahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one V(2), and two equivalent V(1) atoms to form distorted OMgV3 tetrahedra that share corners with three equivalent O(2)Mg2V3 square pyramids, corners with two equivalent O(1)MgV3 tetrahedra, corners with four equivalent O(3)Mg3V2 trigonal bipyramids, and  an edgeedge with one O(3)Mg3V2 trigonal bipyramid. In the second O site, O(2) is bonded to two equivalent Mg(2) and three equivalent V(2) atoms to form OMg2V3 square pyramids that share corners with three equivalent O(1)MgV3 tetrahedra, corners with two equivalent O(3)Mg3V2 trigonal bipyramids, and edges with four equivalent O(2)Mg2V3 square pyramids. In the third O site, O(3) is bonded to one Mg(2), two equivalent Mg(1), and two equivalent V(1) atoms to form distorted OMg3V2 trigonal bipyramids that share corners with two equivalent O(2)Mg2V3 square pyramids, corners with four equivalent O(1)MgV3 tetrahedra,  an edgeedge with one O(1)MgV3 tetrahedra, and edges with two equivalent O(3)Mg3V2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(1), and two equivalent V(2) atoms.
Mg1VO2 crystallizes in the monoclinic C2/m space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO5 trigonal bipyramids that share corners with two equivalent V(2)O6 octahedra, corners with four equivalent Mg(2)O4 tetrahedra, edges with two equivalent Mg(1)O5 trigonal bipyramids, and  a faceface with one V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 44°. The Mg(1)-O(1) bond length is 2.02 Å. Both Mg(1)-O(3) bond lengths are 2.21 Å. Both Mg(1)-O(4) bond lengths are 2.06 Å. In the second Mg site, Mg(2) is bonded to one O(3), one O(4), and two equivalent O(2) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent V(2)O6 octahedra, corners with two equivalent Mg(2)O4 tetrahedra, corners with four equivalent Mg(1)O5 trigonal bipyramids, and edges with three equivalent V(2)O6 octahedra. The corner-sharing octahedral tilt angles are 4°. The Mg(2)-O(3) bond length is 1.95 Å. The Mg(2)-O(4) bond length is 1.97 Å. Both Mg(2)-O(2) bond lengths are 2.01 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both V(1)-O(1) bond lengths are 1.99 Å. Both V(1)-O(3) bond lengths are 2.19 Å. In the second V site, V(2) is bonded to one O(1), two equivalent O(4), and three equivalent O(2) atoms to form distorted VO6 octahedra that share corners with two equivalent Mg(2)O4 tetrahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, edges with four equivalent V(2)O6 octahedra, edges with three equivalent Mg(2)O4 tetrahedra, and  a faceface with one Mg(1)O5 trigonal bipyramid. The V(2)-O(1) bond length is 2.22 Å. Both V(2)-O(4) bond lengths are 2.25 Å. There are two shorter (2.15 Å) and one longer (2.30 Å) V(2)-O(2) bond length. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one V(2), and two equivalent V(1) atoms to form distorted OMgV3 tetrahedra that share corners with three equivalent O(2)Mg2V3 square pyramids, corners with two equivalent O(1)MgV3 tetrahedra, corners with four equivalent O(3)Mg3V2 trigonal bipyramids, and  an edgeedge with one O(3)Mg3V2 trigonal bipyramid. In the second O site, O(2) is bonded to two equivalent Mg(2) and three equivalent V(2) atoms to form OMg2V3 square pyramids that share corners with three equivalent O(1)MgV3 tetrahedra, corners with two equivalent O(3)Mg3V2 trigonal bipyramids, and edges with four equivalent O(2)Mg2V3 square pyramids. In the third O site, O(3) is bonded to one Mg(2), two equivalent Mg(1), and two equivalent V(1) atoms to form distorted OMg3V2 trigonal bipyramids that share corners with two equivalent O(2)Mg2V3 square pyramids, corners with four equivalent O(1)MgV3 tetrahedra,  an edgeedge with one O(1)MgV3 tetrahedra, and edges with two equivalent O(3)Mg3V2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to one Mg(2), two equivalent Mg(1), and two equivalent V(2) atoms.