MgV2Cr4O12 crystallizes in the triclinic P1 space group. Mg(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(10), one O(7), and one O(8) atom. There are two inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(3), and one O(4) atom. In the second V site, V(2) is bonded to one O(11), one O(2), one O(5), one O(6), one O(8), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Cr(2)O5 trigonal bipyramids,  an edgeedge with one Cr(3)O6 octahedra, and  an edgeedge with one Cr(4)O6 octahedra. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(2), and one O(5) atom. 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 V(2)O6 octahedra and corners with three equivalent Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. 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  an edgeedge with one V(2)O6 octahedra and  an edgeedge with one Cr(4)O6 octahedra. 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 Cr(2)O5 trigonal bipyramids,  an edgeedge with one V(2)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one V(1), one Cr(1), and one Cr(3) atom. In the second O site, O(2) is bonded in a 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 distorted 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 3-coordinate 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 planar geometry to one V(2), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in an L-shaped 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 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 distorted T-shaped 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 rectangular see-saw-like geometry to one Mg(1), one V(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 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 in a distorted rectangular see-saw-like geometry to one O(1), one O(10), one O(7), and one O(8) atom. The Mg(1)-O(1) bond length is 1.99 Å. The Mg(1)-O(10) bond length is 2.00 Å. The Mg(1)-O(7) bond length is 1.88 Å. The Mg(1)-O(8) bond length is 1.91 Å. There are two inequivalent V sites. In the first V site, V(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(12), one O(3), and one O(4) atom. The V(1)-O(1) bond length is 2.00 Å. The V(1)-O(10) bond length is 1.99 Å. The V(1)-O(12) bond length is 1.83 Å. The V(1)-O(3) bond length is 1.83 Å. The V(1)-O(4) bond length is 1.74 Å. In the second V site, V(2) is bonded to one O(11), one O(2), one O(5), one O(6), one O(8), and one O(9) atom to form VO6 octahedra that share corners with three equivalent Cr(2)O5 trigonal bipyramids,  an edgeedge with one Cr(3)O6 octahedra, and  an edgeedge with one Cr(4)O6 octahedra. The V(2)-O(11) bond length is 1.98 Å. The V(2)-O(2) bond length is 1.97 Å. The V(2)-O(5) bond length is 2.00 Å. The V(2)-O(6) bond length is 1.74 Å. The V(2)-O(8) bond length is 1.89 Å. The V(2)-O(9) bond length is 1.94 Å. There are four inequivalent Cr sites. In the first Cr site, Cr(1) is bonded in a 5-coordinate geometry to one O(1), one O(10), one O(11), one O(2), and one O(5) atom. The Cr(1)-O(1) bond length is 2.17 Å. The Cr(1)-O(10) bond length is 2.18 Å. The Cr(1)-O(11) bond length is 1.92 Å. The Cr(1)-O(2) bond length is 1.92 Å. The Cr(1)-O(5) bond length is 1.89 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 V(2)O6 octahedra and corners with three equivalent Cr(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-56°. The Cr(2)-O(11) bond length is 1.97 Å. The Cr(2)-O(12) bond length is 2.02 Å. The Cr(2)-O(2) bond length is 1.97 Å. The Cr(2)-O(3) bond length is 2.02 Å. The Cr(2)-O(9) bond length is 1.99 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  an edgeedge with one V(2)O6 octahedra and  an edgeedge with one Cr(4)O6 octahedra. The Cr(3)-O(1) bond length is 2.06 Å. The Cr(3)-O(10) bond length is 2.06 Å. The Cr(3)-O(4) bond length is 2.04 Å. The Cr(3)-O(5) bond length is 1.97 Å. The Cr(3)-O(7) bond length is 1.96 Å. The Cr(3)-O(8) bond length is 1.98 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 Cr(2)O5 trigonal bipyramids,  an edgeedge with one V(2)O6 octahedra, and  an edgeedge with one Cr(3)O6 octahedra. The Cr(4)-O(12) bond length is 2.02 Å. The Cr(4)-O(3) bond length is 2.02 Å. The Cr(4)-O(4) bond length is 2.19 Å. The Cr(4)-O(6) bond length is 2.00 Å. The Cr(4)-O(7) bond length is 1.88 Å. The Cr(4)-O(9) bond length is 2.00 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Mg(1), one V(1), one Cr(1), and one Cr(3) atom. In the second O site, O(2) is bonded in a 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 distorted 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 3-coordinate 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 planar geometry to one V(2), one Cr(1), and one Cr(3) atom. In the sixth O site, O(6) is bonded in an L-shaped 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 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 distorted T-shaped 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 rectangular see-saw-like geometry to one Mg(1), one V(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 trigonal planar geometry to one V(1), one Cr(2), and one Cr(4) atom.