Sr2MgWCdO6 crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. Mg(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(5) atoms to form distorted MgO5 trigonal bipyramids that share corners with three equivalent W(1)O6 octahedra,  a cornercorner with one Cd(1)O4 tetrahedra,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one Cd(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-35°. W(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form WO6 octahedra that share corners with four equivalent Cd(1)O4 tetrahedra, corners with three equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. Cd(1) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form distorted CdO4 tetrahedra that share corners with four equivalent W(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 38-66°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Mg(1), and one W(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Mg(1), and one W(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Sr(1), one W(1), and one Cd(1) atom. In the fourth O site, O(4) is bonded in a square pyramidal geometry to two equivalent Sr(1), one Mg(1), one W(1), and one Cd(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Mg(1), one W(1), and one Cd(1) atom.
Sr2MgWCdO6 crystallizes in the monoclinic Cm space group. Sr(1) is bonded in a 5-coordinate geometry to one O(1), one O(2), one O(3), one O(4), and one O(5) atom. The Sr(1)-O(1) bond length is 2.55 Å. The Sr(1)-O(2) bond length is 2.49 Å. The Sr(1)-O(3) bond length is 2.43 Å. The Sr(1)-O(4) bond length is 2.45 Å. The Sr(1)-O(5) bond length is 2.57 Å. Mg(1) is bonded to one O(1), one O(2), one O(4), and two equivalent O(5) atoms to form distorted MgO5 trigonal bipyramids that share corners with three equivalent W(1)O6 octahedra,  a cornercorner with one Cd(1)O4 tetrahedra,  an edgeedge with one W(1)O6 octahedra, and  an edgeedge with one Cd(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 13-35°. The Mg(1)-O(1) bond length is 1.97 Å. The Mg(1)-O(2) bond length is 1.96 Å. The Mg(1)-O(4) bond length is 2.21 Å. Both Mg(1)-O(5) bond lengths are 2.35 Å. W(1) is bonded to one O(1), one O(2), one O(3), one O(4), and two equivalent O(5) atoms to form WO6 octahedra that share corners with four equivalent Cd(1)O4 tetrahedra, corners with three equivalent Mg(1)O5 trigonal bipyramids, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The W(1)-O(1) bond length is 2.17 Å. The W(1)-O(2) bond length is 2.04 Å. The W(1)-O(3) bond length is 2.05 Å. The W(1)-O(4) bond length is 2.19 Å. Both W(1)-O(5) bond lengths are 2.17 Å. Cd(1) is bonded to one O(3), one O(4), and two equivalent O(5) atoms to form distorted CdO4 tetrahedra that share corners with four equivalent W(1)O6 octahedra,  a cornercorner with one Mg(1)O5 trigonal bipyramid, and  an edgeedge with one Mg(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 38-66°. The Cd(1)-O(3) bond length is 2.19 Å. The Cd(1)-O(4) bond length is 2.18 Å. Both Cd(1)-O(5) bond lengths are 2.27 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Mg(1), and one W(1) atom. In the second O site, O(2) is bonded in a distorted rectangular see-saw-like geometry to two equivalent Sr(1), one Mg(1), and one W(1) atom. In the third O site, O(3) is bonded in a rectangular see-saw-like geometry to two equivalent Sr(1), one W(1), and one Cd(1) atom. In the fourth O site, O(4) is bonded in a square pyramidal geometry to two equivalent Sr(1), one Mg(1), one W(1), and one Cd(1) atom. In the fifth O site, O(5) is bonded in a distorted rectangular see-saw-like geometry to one Sr(1), one Mg(1), one W(1), and one Cd(1) atom.