Mg(SnO2)2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Sn(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Sn(1) atoms to form OMg2Sn3 trigonal bipyramids that share corners with five equivalent O(2)Mg2Sn2 tetrahedra, corners with two equivalent O(1)Mg2Sn3 trigonal bipyramids,  an edgeedge with one O(2)Mg2Sn2 tetrahedra, and edges with five equivalent O(1)Mg2Sn3 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Sn(1) atoms to form OMg2Sn2 tetrahedra that share corners with two equivalent O(2)Mg2Sn2 tetrahedra, corners with ten equivalent O(1)Mg2Sn3 trigonal bipyramids, and edges with two equivalent O(1)Mg2Sn3 trigonal bipyramids. In the third O site, O(3) is bonded in a square co-planar geometry to four equivalent Sn(1) atoms.
Mg(SnO2)2 crystallizes in the orthorhombic Cmcm space group. Mg(1) is bonded in a 6-coordinate geometry to two equivalent O(2) and four equivalent O(1) atoms. Both Mg(1)-O(2) bond lengths are 2.10 Å. All Mg(1)-O(1) bond lengths are 2.46 Å. Sn(1) is bonded to one O(2), two equivalent O(3), and three equivalent O(1) atoms to form a mixture of edge and corner-sharing SnO6 octahedra. The corner-sharing octahedral tilt angles range from 0-66°. The Sn(1)-O(2) bond length is 2.22 Å. Both Sn(1)-O(3) bond lengths are 2.30 Å. There are two shorter (2.28 Å) and one longer (2.36 Å) Sn(1)-O(1) bond length. There are three inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Sn(1) atoms to form OMg2Sn3 trigonal bipyramids that share corners with five equivalent O(2)Mg2Sn2 tetrahedra, corners with two equivalent O(1)Mg2Sn3 trigonal bipyramids,  an edgeedge with one O(2)Mg2Sn2 tetrahedra, and edges with five equivalent O(1)Mg2Sn3 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Mg(1) and two equivalent Sn(1) atoms to form OMg2Sn2 tetrahedra that share corners with two equivalent O(2)Mg2Sn2 tetrahedra, corners with ten equivalent O(1)Mg2Sn3 trigonal bipyramids, and edges with two equivalent O(1)Mg2Sn3 trigonal bipyramids. In the third O site, O(3) is bonded in a square co-planar geometry to four equivalent Sn(1) atoms.