MgV2Cr4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(5), one O(7), and one O(8) atom to form MgO5 trigonal bipyramids that share  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one Cr(4)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one V(2)O5 trigonal bipyramid, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-41°. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(12), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with three equivalent Cr(4)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cr(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-57°. In the second V site, V(2) is bonded to one O(11), one O(2), one O(6), one O(8), and one O(9) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Cr(3)O6 octahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Cr(2)O5 trigonal bipyramids, and  an edgeedge with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(11), one O(2), and one O(5) atom to form CrO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one Cr(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-65°. In the second Cr site, Cr(2) is bonded to one O(11), one O(12), one O(2), one O(3), and one O(9) atom to form distorted CrO5 trigonal bipyramids that share corners with three equivalent Cr(4)O6 octahedra, corners with three equivalent V(2)O5 trigonal bipyramids,  an edgeedge with one V(1)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-52°. In the third Cr site, Cr(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one V(2)O5 trigonal bipyramid,  an edgeedge with one Cr(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. In the fourth Cr site, Cr(4) is bonded to one O(12), one O(3), one O(4), one O(6), one O(7), and one O(9) atom to form CrO6 octahedra that share corners with three equivalent V(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Cr(2)O5 trigonal bipyramids,  an edgeedge with one Cr(3)O6 octahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. There are twelve 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 Cr(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(2), one Cr(1), and one Cr(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one V(1), one Cr(2), and one Cr(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one V(1), one Cr(3), and one Cr(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one V(2) and one Cr(4) atom. In the seventh O site, O(7) is bonded in a T-shaped geometry to one Mg(1), one Cr(3), and one Cr(4) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one Cr(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one V(2), one Cr(2), and one Cr(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cr(1), and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one V(2), one Cr(1), and one Cr(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one V(1), one Cr(2), and one Cr(4) atom.
MgV2Cr4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded to one O(1), one O(10), one O(5), one O(7), and one O(8) atom to form MgO5 trigonal bipyramids that share  a cornercorner with one Cr(3)O6 octahedra,  a cornercorner with one Cr(4)O6 octahedra,  a cornercorner with one V(1)O4 tetrahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one V(2)O5 trigonal bipyramid, and edges with two equivalent Cr(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-41°. The Mg(1)-O(1) bond length is 2.00 Å. The Mg(1)-O(10) bond length is 2.02 Å. The Mg(1)-O(5) bond length is 2.13 Å. The Mg(1)-O(7) bond length is 1.94 Å. The Mg(1)-O(8) bond length is 2.09 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded to one O(1), one O(12), one O(3), and one O(4) atom to form VO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with three equivalent Cr(4)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Cr(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 42-57°. The V(1)-O(1) bond length is 1.77 Å. The V(1)-O(12) bond length is 1.86 Å. The V(1)-O(3) bond length is 1.85 Å. The V(1)-O(4) bond length is 1.82 Å. In the second V site, V(2) is bonded to one O(11), one O(2), one O(6), one O(8), and one O(9) atom to form distorted VO5 trigonal bipyramids that share  a cornercorner with one Cr(3)O6 octahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Cr(2)O5 trigonal bipyramids, and  an edgeedge with one Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles are 51°. The V(2)-O(11) bond length is 1.97 Å. The V(2)-O(2) bond length is 2.00 Å. The V(2)-O(6) bond length is 1.72 Å. The V(2)-O(8) bond length is 1.81 Å. The V(2)-O(9) bond length is 1.78 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to one O(10), one O(11), one O(2), and one O(5) atom to form CrO4 tetrahedra that share corners with two equivalent Cr(3)O6 octahedra, corners with two equivalent Mg(1)O5 trigonal bipyramids, corners with two equivalent V(2)O5 trigonal bipyramids, and  an edgeedge with one Cr(2)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 33-65°. The Cr(1)-O(10) bond length is 1.79 Å. The Cr(1)-O(11) bond length is 1.85 Å. The Cr(1)-O(2) bond length is 1.88 Å. The Cr(1)-O(5) bond length is 1.75 Å. In the second Cr site, Cr(2) is bonded to one O(11), one O(12), one O(2), one O(3), and one O(9) atom to form distorted CrO5 trigonal bipyramids that share corners with three equivalent Cr(4)O6 octahedra, corners with three equivalent V(2)O5 trigonal bipyramids,  an edgeedge with one V(1)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-52°. The Cr(2)-O(11) bond length is 1.94 Å. The Cr(2)-O(12) bond length is 2.00 Å. The Cr(2)-O(2) bond length is 2.05 Å. The Cr(2)-O(3) bond length is 1.93 Å. The Cr(2)-O(9) bond length is 2.00 Å. In the third Cr site, Cr(3) is bonded to one O(1), one O(10), one O(4), one O(5), one O(7), and one O(8) atom to form CrO6 octahedra that share corners with two equivalent V(1)O4 tetrahedra, corners with two equivalent Cr(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid,  a cornercorner with one V(2)O5 trigonal bipyramid,  an edgeedge with one Cr(4)O6 octahedra, and edges with two equivalent Mg(1)O5 trigonal bipyramids. The Cr(3)-O(1) bond length is 2.09 Å. The Cr(3)-O(10) bond length is 2.04 Å. The Cr(3)-O(4) bond length is 2.04 Å. The Cr(3)-O(5) bond length is 2.03 Å. The Cr(3)-O(7) bond length is 1.96 Å. The Cr(3)-O(8) bond length is 2.01 Å. In the fourth Cr site, Cr(4) is bonded to one O(12), one O(3), one O(4), one O(6), one O(7), and one O(9) atom to form CrO6 octahedra that share corners with three equivalent V(1)O4 tetrahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, corners with three equivalent Cr(2)O5 trigonal bipyramids,  an edgeedge with one Cr(3)O6 octahedra, and  an edgeedge with one V(2)O5 trigonal bipyramid. The Cr(4)-O(12) bond length is 1.99 Å. The Cr(4)-O(3) bond length is 1.97 Å. The Cr(4)-O(4) bond length is 2.01 Å. The Cr(4)-O(6) bond length is 2.06 Å. The Cr(4)-O(7) bond length is 1.94 Å. The Cr(4)-O(9) bond length is 2.34 Å. There are twelve 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 Cr(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one V(2), one Cr(1), and one Cr(2) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one V(1), one Cr(2), and one Cr(4) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one V(1), one Cr(3), and one Cr(4) atom. In the fifth O site, O(5) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one V(2) and one Cr(4) atom. In the seventh O site, O(7) is bonded in a T-shaped geometry to one Mg(1), one Cr(3), and one Cr(4) atom. In the eighth O site, O(8) is bonded in a distorted T-shaped geometry to one Mg(1), one V(2), and one Cr(3) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one V(2), one Cr(2), and one Cr(4) atom. In the tenth O site, O(10) is bonded in a distorted trigonal planar geometry to one Mg(1), one Cr(1), and one Cr(3) atom. In the eleventh O site, O(11) is bonded in a trigonal planar geometry to one V(2), one Cr(1), and one Cr(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal planar geometry to one V(1), one Cr(2), and one Cr(4) atom.