Mg(MoO2)2 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to one O(2), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO7 pentagonal bipyramids that share corners with four equivalent Mo(1)O6 octahedra, corners with six equivalent Mo(2)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, edges with three equivalent Mo(1)O6 octahedra,  a faceface with one Mo(2)O6 octahedra, and faces with two equivalent Mg(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 28-68°. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(4), two equivalent O(2), and three equivalent O(3) atoms to form MoO6 octahedra that share corners with four equivalent Mo(2)O6 octahedra, corners with four equivalent Mg(1)O7 pentagonal bipyramids, edges with four equivalent Mo(1)O6 octahedra, and edges with three equivalent Mg(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 53-65°. In the second Mo site, Mo(2) is bonded to one O(2), two equivalent O(4), and three equivalent O(1) atoms to form MoO6 octahedra that share corners with four equivalent Mo(1)O6 octahedra, corners with six equivalent Mg(1)O7 pentagonal bipyramids, edges with four equivalent Mo(2)O6 octahedra,  an edgeedge with one Mg(1)O7 pentagonal bipyramid, and  a faceface with one Mg(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 53-65°. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Mo(2) atoms to form distorted OMg2Mo3 trigonal bipyramids that share  a cornercorner with one O(2)MgMo3 tetrahedra, corners with two equivalent O(3)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(4)Mg2Mo3 trigonal bipyramids, edges with two equivalent O(2)MgMo3 tetrahedra,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids, and edges with four equivalent O(1)Mg2Mo3 trigonal bipyramids. In the second O site, O(2) is bonded to one Mg(1), one Mo(2), and two equivalent Mo(1) atoms to form OMgMo3 tetrahedra that share corners with two equivalent O(2)MgMo3 tetrahedra,  a cornercorner with one O(1)Mg2Mo3 trigonal bipyramid, corners with two equivalent O(4)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(3)Mg2Mo3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(1)Mg2Mo3 trigonal bipyramids, and edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Mg(1) and three equivalent Mo(1) atoms to form OMg2Mo3 trigonal bipyramids that share corners with six equivalent O(2)MgMo3 tetrahedra, corners with two equivalent O(1)Mg2Mo3 trigonal bipyramids, corners with five equivalent O(4)Mg2Mo3 trigonal bipyramids,  an edgeedge with one O(2)MgMo3 tetrahedra,  an edgeedge with one O(1)Mg2Mo3 trigonal bipyramid,  an edgeedge with one O(4)Mg2Mo3 trigonal bipyramid, and edges with four equivalent O(3)Mg2Mo3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Mo(1), and two equivalent Mo(2) atoms to form distorted OMg2Mo3 trigonal bipyramids that share corners with two equivalent O(2)MgMo3 tetrahedra, corners with five equivalent O(3)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(1)Mg2Mo3 trigonal bipyramids, edges with two equivalent O(2)MgMo3 tetrahedra,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(1)Mg2Mo3 trigonal bipyramids, and edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids.
Mg(MoO2)2 crystallizes in the orthorhombic Pnma space group. Mg(1) is bonded to one O(2), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form distorted MgO7 pentagonal bipyramids that share corners with four equivalent Mo(1)O6 octahedra, corners with six equivalent Mo(2)O6 octahedra,  an edgeedge with one Mo(2)O6 octahedra, edges with three equivalent Mo(1)O6 octahedra,  a faceface with one Mo(2)O6 octahedra, and faces with two equivalent Mg(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 28-68°. The Mg(1)-O(2) bond length is 2.16 Å. Both Mg(1)-O(1) bond lengths are 2.35 Å. Both Mg(1)-O(3) bond lengths are 2.35 Å. Both Mg(1)-O(4) bond lengths are 2.40 Å. There are two inequivalent Mo sites. In the first Mo site, Mo(1) is bonded to one O(4), two equivalent O(2), and three equivalent O(3) atoms to form MoO6 octahedra that share corners with four equivalent Mo(2)O6 octahedra, corners with four equivalent Mg(1)O7 pentagonal bipyramids, edges with four equivalent Mo(1)O6 octahedra, and edges with three equivalent Mg(1)O7 pentagonal bipyramids. The corner-sharing octahedral tilt angles range from 53-65°. The Mo(1)-O(4) bond length is 2.22 Å. Both Mo(1)-O(2) bond lengths are 2.09 Å. There is one shorter (2.20 Å) and two longer (2.24 Å) Mo(1)-O(3) bond lengths. In the second Mo site, Mo(2) is bonded to one O(2), two equivalent O(4), and three equivalent O(1) atoms to form MoO6 octahedra that share corners with four equivalent Mo(1)O6 octahedra, corners with six equivalent Mg(1)O7 pentagonal bipyramids, edges with four equivalent Mo(2)O6 octahedra,  an edgeedge with one Mg(1)O7 pentagonal bipyramid, and  a faceface with one Mg(1)O7 pentagonal bipyramid. The corner-sharing octahedral tilt angles range from 53-65°. The Mo(2)-O(2) bond length is 2.10 Å. Both Mo(2)-O(4) bond lengths are 2.19 Å. There is one shorter (2.19 Å) and two longer (2.20 Å) Mo(2)-O(1) bond lengths. There are four inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Mg(1) and three equivalent Mo(2) atoms to form distorted OMg2Mo3 trigonal bipyramids that share  a cornercorner with one O(2)MgMo3 tetrahedra, corners with two equivalent O(3)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(4)Mg2Mo3 trigonal bipyramids, edges with two equivalent O(2)MgMo3 tetrahedra,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids, and edges with four equivalent O(1)Mg2Mo3 trigonal bipyramids. In the second O site, O(2) is bonded to one Mg(1), one Mo(2), and two equivalent Mo(1) atoms to form OMgMo3 tetrahedra that share corners with two equivalent O(2)MgMo3 tetrahedra,  a cornercorner with one O(1)Mg2Mo3 trigonal bipyramid, corners with two equivalent O(4)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(3)Mg2Mo3 trigonal bipyramids,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(1)Mg2Mo3 trigonal bipyramids, and edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids. In the third O site, O(3) is bonded to two equivalent Mg(1) and three equivalent Mo(1) atoms to form OMg2Mo3 trigonal bipyramids that share corners with six equivalent O(2)MgMo3 tetrahedra, corners with two equivalent O(1)Mg2Mo3 trigonal bipyramids, corners with five equivalent O(4)Mg2Mo3 trigonal bipyramids,  an edgeedge with one O(2)MgMo3 tetrahedra,  an edgeedge with one O(1)Mg2Mo3 trigonal bipyramid,  an edgeedge with one O(4)Mg2Mo3 trigonal bipyramid, and edges with four equivalent O(3)Mg2Mo3 trigonal bipyramids. In the fourth O site, O(4) is bonded to two equivalent Mg(1), one Mo(1), and two equivalent Mo(2) atoms to form distorted OMg2Mo3 trigonal bipyramids that share corners with two equivalent O(2)MgMo3 tetrahedra, corners with five equivalent O(3)Mg2Mo3 trigonal bipyramids, corners with six equivalent O(1)Mg2Mo3 trigonal bipyramids, edges with two equivalent O(2)MgMo3 tetrahedra,  an edgeedge with one O(3)Mg2Mo3 trigonal bipyramid, edges with two equivalent O(1)Mg2Mo3 trigonal bipyramids, and edges with two equivalent O(4)Mg2Mo3 trigonal bipyramids.