MgCr2Cu2(WO4)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. In the second W site, W(2) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form distorted WO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra, and corners with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-56°. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with four equivalent W(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-52°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form CuO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(8) atoms to form distorted CuO6 octahedra that share corners with four equivalent W(2)O6 octahedra and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one W(2), one Cr(1), and one Cu(2) atom. In the second O site, O(2) is bonded to one Mg(1), one W(1), one Cr(2), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OMgCrCuW trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Cr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one W(1), one Cr(1), and one Cu(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one W(2), one Cr(2), and one Cu(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Cu(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Cu(2) atom.
MgCr2Cu2(WO4)4 crystallizes in the monoclinic C2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form MgO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Cr(1)O6 octahedra,  an edgeedge with one Cu(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-52°. Both Mg(1)-O(2) bond lengths are 2.00 Å. Both Mg(1)-O(3) bond lengths are 2.05 Å. Both Mg(1)-O(4) bond lengths are 2.04 Å. There are two inequivalent W sites. In the first W site, W(1) is bonded in a 6-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(7), and one O(8) atom. The W(1)-O(2) bond length is 2.01 Å. The W(1)-O(3) bond length is 2.40 Å. The W(1)-O(4) bond length is 2.07 Å. The W(1)-O(5) bond length is 1.84 Å. The W(1)-O(7) bond length is 2.04 Å. The W(1)-O(8) bond length is 1.98 Å. In the second W site, W(2) is bonded to one O(1), one O(3), one O(4), one O(6), one O(7), and one O(8) atom to form distorted WO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Cr(1)O6 octahedra, corners with two equivalent Cr(2)O6 octahedra, corners with two equivalent Cu(1)O6 octahedra, and corners with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-56°. The W(2)-O(1) bond length is 1.86 Å. The W(2)-O(3) bond length is 2.02 Å. The W(2)-O(4) bond length is 2.25 Å. The W(2)-O(6) bond length is 1.86 Å. The W(2)-O(7) bond length is 1.95 Å. The W(2)-O(8) bond length is 2.01 Å. There are two inequivalent Cr sites. In the first Cr site, Cr(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form CrO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cu(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-54°. Both Cr(1)-O(1) bond lengths are 2.01 Å. Both Cr(1)-O(3) bond lengths are 2.09 Å. Both Cr(1)-O(5) bond lengths are 1.98 Å. In the second Cr site, Cr(2) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form CrO6 octahedra that share corners with four equivalent W(2)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent Cu(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-52°. Both Cr(2)-O(2) bond lengths are 2.02 Å. Both Cr(2)-O(4) bond lengths are 2.14 Å. Both Cr(2)-O(6) bond lengths are 2.05 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2), two equivalent O(6), and two equivalent O(7) atoms to form CuO6 octahedra that share corners with four equivalent W(2)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Cr(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 55-56°. Both Cu(1)-O(2) bond lengths are 2.36 Å. Both Cu(1)-O(6) bond lengths are 2.21 Å. Both Cu(1)-O(7) bond lengths are 2.15 Å. In the second Cu site, Cu(2) is bonded to two equivalent O(1), two equivalent O(5), and two equivalent O(8) atoms to form distorted CuO6 octahedra that share corners with four equivalent W(2)O6 octahedra and edges with two equivalent Cr(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-52°. Both Cu(2)-O(1) bond lengths are 2.41 Å. Both Cu(2)-O(5) bond lengths are 2.05 Å. Both Cu(2)-O(8) bond lengths are 2.12 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one W(2), one Cr(1), and one Cu(2) atom. In the second O site, O(2) is bonded to one Mg(1), one W(1), one Cr(2), and one Cu(1) atom to form a mixture of distorted corner and edge-sharing OMgCrCuW trigonal pyramids. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Cr(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one W(1), one W(2), and one Cr(2) atom. In the fifth O site, O(5) is bonded in a trigonal planar geometry to one W(1), one Cr(1), and one Cu(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one W(2), one Cr(2), and one Cu(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Cu(1) atom. In the eighth O site, O(8) is bonded in a trigonal planar geometry to one W(1), one W(2), and one Cu(2) atom.