MgCr2Zn2O8 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-68°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form CrO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. In the second Cr site, Cr(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-50°. Zn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form ZnO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Zn(1)O6 octahedra. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(2) and two equivalent Zn(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Cr(1), and two equivalent Zn(1) atoms to form distorted edge-sharing OMgZn2Cr tetrahedra. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Zn(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cr(1) and one Zn(1) atom.
MgCr2Zn2O8 crystallizes in the orthorhombic Amm2 space group. Mg(1) is bonded to two equivalent O(2) and two equivalent O(3) atoms to form distorted MgO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra, corners with two equivalent Cr(2)O4 tetrahedra, and  an edgeedge with one Cr(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 66-68°. Both Mg(1)-O(2) bond lengths are 2.04 Å. Both Mg(1)-O(3) bond lengths are 1.97 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(2) and two equivalent O(4) atoms to form CrO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra and  an edgeedge with one Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 51-58°. Both Cr(1)-O(2) bond lengths are 1.84 Å. Both Cr(1)-O(4) bond lengths are 1.65 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(1) and two equivalent O(3) atoms to form CrO4 tetrahedra that share corners with six equivalent Zn(1)O6 octahedra and corners with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 49-50°. Both Cr(2)-O(1) bond lengths are 1.71 Å. Both Cr(2)-O(3) bond lengths are 1.76 Å. Zn(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form ZnO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra, corners with three equivalent Cr(1)O4 tetrahedra, corners with three equivalent Cr(2)O4 tetrahedra, and edges with two equivalent Zn(1)O6 octahedra. The Zn(1)-O(3) bond length is 2.05 Å. The Zn(1)-O(4) bond length is 2.09 Å. Both Zn(1)-O(1) bond lengths are 2.14 Å. Both Zn(1)-O(2) bond lengths are 2.22 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Cr(2) and two equivalent Zn(1) atoms. In the second O site, O(2) is bonded to one Mg(1), one Cr(1), and two equivalent Zn(1) atoms to form distorted edge-sharing OMgZn2Cr tetrahedra. In the third O site, O(3) is bonded in a trigonal planar geometry to one Mg(1), one Cr(2), and one Zn(1) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Cr(1) and one Zn(1) atom.