MgV2O4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted MgO6 pentagonal pyramids that share corners with six equivalent V(1)O6 octahedra, edges with two equivalent V(1)O6 octahedra, edges with four equivalent V(2)O6 octahedra, and edges with two equivalent Mg(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 4-14°. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted MgO6 pentagonal pyramids that share corners with four equivalent V(1)O6 octahedra, corners with eight equivalent V(2)O6 octahedra, edges with two equivalent Mg(1)O6 pentagonal pyramids, and faces with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form VO6 octahedra that share corners with two equivalent Mg(2)O6 pentagonal pyramids, corners with three equivalent Mg(1)O6 pentagonal pyramids, edges with two equivalent V(1)O6 octahedra, edges with four equivalent V(2)O6 octahedra,  an edgeedge with one Mg(1)O6 pentagonal pyramid, and  a faceface with one Mg(2)O6 pentagonal pyramid. In the second V site, V(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form VO6 octahedra that share corners with four equivalent Mg(2)O6 pentagonal pyramids, edges with two equivalent V(2)O6 octahedra, edges with four equivalent V(1)O6 octahedra, and edges with two equivalent Mg(1)O6 pentagonal pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), and two equivalent V(2) atoms. In the second O site, O(2) is bonded to one Mg(2), one V(1), and two equivalent V(2) atoms to form OMgV3 trigonal pyramids that share corners with four equivalent O(3)Mg2V3 trigonal bipyramids, corners with three equivalent O(2)MgV3 trigonal pyramids, and edges with four equivalent O(3)Mg2V3 trigonal bipyramids. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), one V(2), and two equivalent V(1) atoms to form OMg2V3 trigonal bipyramids that share corners with five equivalent O(3)Mg2V3 trigonal bipyramids, corners with two equivalent O(2)MgV3 trigonal pyramids, edges with four equivalent O(3)Mg2V3 trigonal bipyramids, and edges with two equivalent O(2)MgV3 trigonal pyramids.
MgV2O4 crystallizes in the orthorhombic Pmmn space group. There are two inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to two equivalent O(1) and four equivalent O(3) atoms to form distorted MgO6 pentagonal pyramids that share corners with six equivalent V(1)O6 octahedra, edges with two equivalent V(1)O6 octahedra, edges with four equivalent V(2)O6 octahedra, and edges with two equivalent Mg(2)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles range from 4-14°. Both Mg(1)-O(1) bond lengths are 2.14 Å. All Mg(1)-O(3) bond lengths are 2.26 Å. In the second Mg site, Mg(2) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form distorted MgO6 pentagonal pyramids that share corners with four equivalent V(1)O6 octahedra, corners with eight equivalent V(2)O6 octahedra, edges with two equivalent Mg(1)O6 pentagonal pyramids, and faces with two equivalent V(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. Both Mg(2)-O(2) bond lengths are 2.22 Å. All Mg(2)-O(3) bond lengths are 2.20 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(2), and four equivalent O(3) atoms to form VO6 octahedra that share corners with two equivalent Mg(2)O6 pentagonal pyramids, corners with three equivalent Mg(1)O6 pentagonal pyramids, edges with two equivalent V(1)O6 octahedra, edges with four equivalent V(2)O6 octahedra,  an edgeedge with one Mg(1)O6 pentagonal pyramid, and  a faceface with one Mg(2)O6 pentagonal pyramid. The V(1)-O(1) bond length is 2.03 Å. The V(1)-O(2) bond length is 2.01 Å. There are two shorter (2.03 Å) and two longer (2.12 Å) V(1)-O(3) bond lengths. In the second V site, V(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form VO6 octahedra that share corners with four equivalent Mg(2)O6 pentagonal pyramids, edges with two equivalent V(2)O6 octahedra, edges with four equivalent V(1)O6 octahedra, and edges with two equivalent Mg(1)O6 pentagonal pyramids. Both V(2)-O(1) bond lengths are 2.01 Å. Both V(2)-O(2) bond lengths are 2.04 Å. Both V(2)-O(3) bond lengths are 2.13 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Mg(1), one V(1), and two equivalent V(2) atoms. In the second O site, O(2) is bonded to one Mg(2), one V(1), and two equivalent V(2) atoms to form OMgV3 trigonal pyramids that share corners with four equivalent O(3)Mg2V3 trigonal bipyramids, corners with three equivalent O(2)MgV3 trigonal pyramids, and edges with four equivalent O(3)Mg2V3 trigonal bipyramids. In the third O site, O(3) is bonded to one Mg(1), one Mg(2), one V(2), and two equivalent V(1) atoms to form OMg2V3 trigonal bipyramids that share corners with five equivalent O(3)Mg2V3 trigonal bipyramids, corners with two equivalent O(2)MgV3 trigonal pyramids, edges with four equivalent O(3)Mg2V3 trigonal bipyramids, and edges with two equivalent O(2)MgV3 trigonal pyramids.