MgWO2 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(6), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra,  a cornercorner with one Mg(2)O5 trigonal bipyramid, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(5), and two equivalent O(8) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, and edges with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 63-67°. In the third Mg site, Mg(3) is bonded to one O(7), one O(8), and two equivalent O(3) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 39-62°. In the fourth Mg site, Mg(4) is bonded to one O(3), one O(5), two equivalent O(2), and two equivalent O(6) atoms to form distorted MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, corners with two equivalent Mg(2)O5 trigonal bipyramids, and edges with two equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. There are four inequivalent W sites. In the first W site, W(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), and two equivalent O(5) atoms. In the second W site, W(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(6) atoms. In the third W site, W(3) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(8) atom. In the fourth W site, W(4) is bonded in a 3-coordinate geometry to one O(7) and two equivalent O(1) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), one W(3), and two equivalent W(4) atoms to form distorted OMg2W3 square pyramids that share corners with two equivalent O(1)Mg2W3 square pyramids,  a cornercorner with one O(6)Mg3W2 trigonal bipyramid, corners with two equivalent O(5)Mg3W2 trigonal bipyramids,  a cornercorner with one O(8)Mg3W trigonal pyramid,  an edgeedge with one O(8)Mg3W trigonal pyramid, and edges with two equivalent O(7)Mg3W trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Mg(4), one W(1), and one W(3) atom. In the third O site, O(3) is bonded to one Mg(4), two equivalent Mg(3), and one W(2) atom to form distorted OMg3W tetrahedra that share corners with two equivalent O(3)Mg3W tetrahedra,  a cornercorner with one O(5)Mg3W2 trigonal bipyramid, corners with two equivalent O(7)Mg3W trigonal pyramids, corners with two equivalent O(8)Mg3W trigonal pyramids, and edges with two equivalent O(6)Mg3W2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1), one W(1), and one W(2) atom. In the fifth O site, O(5) is bonded to one Mg(4), two equivalent Mg(2), and two equivalent W(1) atoms to form distorted OMg3W2 trigonal bipyramids that share corners with two equivalent O(1)Mg2W3 square pyramids,  a cornercorner with one O(3)Mg3W tetrahedra, corners with two equivalent O(6)Mg3W2 trigonal bipyramids, corners with two equivalent O(8)Mg3W trigonal pyramids, edges with two equivalent O(5)Mg3W2 trigonal bipyramids, and  an edgeedge with one O(8)Mg3W trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(1), two equivalent Mg(4), and two equivalent W(2) atoms to form distorted OMg3W2 trigonal bipyramids that share  a cornercorner with one O(1)Mg2W3 square pyramid, corners with two equivalent O(5)Mg3W2 trigonal bipyramids, corners with two equivalent O(7)Mg3W trigonal pyramids, edges with two equivalent O(3)Mg3W tetrahedra, and edges with two equivalent O(6)Mg3W2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Mg(3), two equivalent Mg(1), and one W(4) atom to form distorted OMg3W trigonal pyramids that share corners with two equivalent O(3)Mg3W tetrahedra, corners with two equivalent O(6)Mg3W2 trigonal bipyramids,  a cornercorner with one O(8)Mg3W trigonal pyramid, corners with two equivalent O(7)Mg3W trigonal pyramids, and edges with two equivalent O(1)Mg2W3 square pyramids. In the eighth O site, O(8) is bonded to one Mg(3), two equivalent Mg(2), and one W(3) atom to form distorted OMg3W trigonal pyramids that share  a cornercorner with one O(1)Mg2W3 square pyramid, corners with two equivalent O(3)Mg3W tetrahedra, corners with two equivalent O(5)Mg3W2 trigonal bipyramids,  a cornercorner with one O(7)Mg3W trigonal pyramid, corners with two equivalent O(8)Mg3W trigonal pyramids,  an edgeedge with one O(1)Mg2W3 square pyramid, and  an edgeedge with one O(5)Mg3W2 trigonal bipyramid.
MgWO2 crystallizes in the triclinic P1 space group. There are four inequivalent Mg sites. In the first Mg site, Mg(1) is bonded to one O(1), one O(6), two equivalent O(4), and two equivalent O(7) atoms to form MgO6 octahedra that share corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra,  a cornercorner with one Mg(2)O5 trigonal bipyramid, and edges with two equivalent Mg(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Mg(1)-O(1) bond length is 2.24 Å. The Mg(1)-O(6) bond length is 2.20 Å. There is one shorter (2.03 Å) and one longer (2.12 Å) Mg(1)-O(4) bond length. There is one shorter (2.05 Å) and one longer (2.09 Å) Mg(1)-O(7) bond length. In the second Mg site, Mg(2) is bonded to one O(1), two equivalent O(5), and two equivalent O(8) atoms to form distorted MgO5 trigonal bipyramids that share  a cornercorner with one Mg(1)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, and edges with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 63-67°. The Mg(2)-O(1) bond length is 2.11 Å. There is one shorter (2.07 Å) and one longer (2.16 Å) Mg(2)-O(5) bond length. There is one shorter (2.08 Å) and one longer (2.12 Å) Mg(2)-O(8) bond length. In the third Mg site, Mg(3) is bonded to one O(7), one O(8), and two equivalent O(3) atoms to form MgO4 tetrahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(4)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, and corners with two equivalent Mg(2)O5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 39-62°. The Mg(3)-O(7) bond length is 2.00 Å. The Mg(3)-O(8) bond length is 2.02 Å. Both Mg(3)-O(3) bond lengths are 1.95 Å. In the fourth Mg site, Mg(4) is bonded to one O(3), one O(5), two equivalent O(2), and two equivalent O(6) atoms to form distorted MgO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent Mg(3)O4 tetrahedra, corners with two equivalent Mg(2)O5 trigonal bipyramids, and edges with two equivalent Mg(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Mg(4)-O(3) bond length is 2.05 Å. The Mg(4)-O(5) bond length is 2.43 Å. There is one shorter (2.02 Å) and one longer (2.07 Å) Mg(4)-O(2) bond length. There is one shorter (2.12 Å) and one longer (2.19 Å) Mg(4)-O(6) bond length. There are four inequivalent W sites. In the first W site, W(1) is bonded in a 4-coordinate geometry to one O(2), one O(4), and two equivalent O(5) atoms. The W(1)-O(2) bond length is 2.12 Å. The W(1)-O(4) bond length is 2.11 Å. There is one shorter (2.19 Å) and one longer (2.29 Å) W(1)-O(5) bond length. In the second W site, W(2) is bonded in a 4-coordinate geometry to one O(3), one O(4), and two equivalent O(6) atoms. The W(2)-O(3) bond length is 2.06 Å. The W(2)-O(4) bond length is 2.10 Å. There is one shorter (2.28 Å) and one longer (2.30 Å) W(2)-O(6) bond length. In the third W site, W(3) is bonded in a 3-coordinate geometry to one O(1), one O(2), and one O(8) atom. The W(3)-O(1) bond length is 2.19 Å. The W(3)-O(2) bond length is 2.07 Å. The W(3)-O(8) bond length is 2.11 Å. In the fourth W site, W(4) is bonded in a 3-coordinate geometry to one O(7) and two equivalent O(1) atoms. The W(4)-O(7) bond length is 2.11 Å. There is one shorter (2.21 Å) and one longer (2.22 Å) W(4)-O(1) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Mg(2), one W(3), and two equivalent W(4) atoms to form distorted OMg2W3 square pyramids that share corners with two equivalent O(1)Mg2W3 square pyramids,  a cornercorner with one O(6)Mg3W2 trigonal bipyramid, corners with two equivalent O(5)Mg3W2 trigonal bipyramids,  a cornercorner with one O(8)Mg3W trigonal pyramid,  an edgeedge with one O(8)Mg3W trigonal pyramid, and edges with two equivalent O(7)Mg3W trigonal pyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Mg(4), one W(1), and one W(3) atom. In the third O site, O(3) is bonded to one Mg(4), two equivalent Mg(3), and one W(2) atom to form distorted OMg3W tetrahedra that share corners with two equivalent O(3)Mg3W tetrahedra,  a cornercorner with one O(5)Mg3W2 trigonal bipyramid, corners with two equivalent O(7)Mg3W trigonal pyramids, corners with two equivalent O(8)Mg3W trigonal pyramids, and edges with two equivalent O(6)Mg3W2 trigonal bipyramids. In the fourth O site, O(4) is bonded in a distorted see-saw-like geometry to two equivalent Mg(1), one W(1), and one W(2) atom. In the fifth O site, O(5) is bonded to one Mg(4), two equivalent Mg(2), and two equivalent W(1) atoms to form distorted OMg3W2 trigonal bipyramids that share corners with two equivalent O(1)Mg2W3 square pyramids,  a cornercorner with one O(3)Mg3W tetrahedra, corners with two equivalent O(6)Mg3W2 trigonal bipyramids, corners with two equivalent O(8)Mg3W trigonal pyramids, edges with two equivalent O(5)Mg3W2 trigonal bipyramids, and  an edgeedge with one O(8)Mg3W trigonal pyramid. In the sixth O site, O(6) is bonded to one Mg(1), two equivalent Mg(4), and two equivalent W(2) atoms to form distorted OMg3W2 trigonal bipyramids that share  a cornercorner with one O(1)Mg2W3 square pyramid, corners with two equivalent O(5)Mg3W2 trigonal bipyramids, corners with two equivalent O(7)Mg3W trigonal pyramids, edges with two equivalent O(3)Mg3W tetrahedra, and edges with two equivalent O(6)Mg3W2 trigonal bipyramids. In the seventh O site, O(7) is bonded to one Mg(3), two equivalent Mg(1), and one W(4) atom to form distorted OMg3W trigonal pyramids that share corners with two equivalent O(3)Mg3W tetrahedra, corners with two equivalent O(6)Mg3W2 trigonal bipyramids,  a cornercorner with one O(8)Mg3W trigonal pyramid, corners with two equivalent O(7)Mg3W trigonal pyramids, and edges with two equivalent O(1)Mg2W3 square pyramids. In the eighth O site, O(8) is bonded to one Mg(3), two equivalent Mg(2), and one W(3) atom to form distorted OMg3W trigonal pyramids that share  a cornercorner with one O(1)Mg2W3 square pyramid, corners with two equivalent O(3)Mg3W tetrahedra, corners with two equivalent O(5)Mg3W2 trigonal bipyramids,  a cornercorner with one O(7)Mg3W trigonal pyramid, corners with two equivalent O(8)Mg3W trigonal pyramids,  an edgeedge with one O(1)Mg2W3 square pyramid, and  an edgeedge with one O(5)Mg3W2 trigonal bipyramid.