MgWTe3O12 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted MgO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, corners with four equivalent Te(3)O6 octahedra,  an edgeedge with one W(1)O6 octahedra, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. W(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with two equivalent Te(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent W(1)O6 octahedra, and edges with two equivalent Te(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. In the second Te site, Te(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with two equivalent Te(3)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. In the third Te site, Te(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form distorted TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-55°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one W(1) and one Te(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Te(1), and one Te(3) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one W(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Te(1) and one Te(3) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one W(1) and one Te(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Te(2), and one Te(3) atom.
MgWTe3O12 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form distorted MgO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, corners with four equivalent Te(3)O6 octahedra,  an edgeedge with one W(1)O6 octahedra, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 47-55°. Both Mg(1)-O(2) bond lengths are 2.07 Å. Both Mg(1)-O(3) bond lengths are 2.36 Å. Both Mg(1)-O(6) bond lengths are 2.08 Å. W(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form distorted WO6 octahedra that share corners with two equivalent Te(1)O6 octahedra,  an edgeedge with one Mg(1)O6 octahedra, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles are 32°. Both W(1)-O(1) bond lengths are 1.90 Å. Both W(1)-O(3) bond lengths are 2.04 Å. Both W(1)-O(5) bond lengths are 1.96 Å. There are three inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(4) atoms to form TeO6 octahedra that share corners with two equivalent Mg(1)O6 octahedra, corners with two equivalent W(1)O6 octahedra, and edges with two equivalent Te(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-47°. Both Te(1)-O(1) bond lengths are 1.98 Å. Both Te(1)-O(2) bond lengths are 1.97 Å. Both Te(1)-O(4) bond lengths are 1.93 Å. In the second Te site, Te(2) is bonded to two equivalent O(3), two equivalent O(5), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with two equivalent Te(3)O6 octahedra, edges with two equivalent Mg(1)O6 octahedra, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 55°. Both Te(2)-O(3) bond lengths are 2.00 Å. Both Te(2)-O(5) bond lengths are 1.98 Å. Both Te(2)-O(6) bond lengths are 1.91 Å. In the third Te site, Te(3) is bonded to two equivalent O(2), two equivalent O(4), and two equivalent O(6) atoms to form distorted TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra, corners with four equivalent Mg(1)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 54-55°. Both Te(3)-O(2) bond lengths are 2.17 Å. Both Te(3)-O(4) bond lengths are 2.05 Å. Both Te(3)-O(6) bond lengths are 2.36 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one W(1) and one Te(1) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Mg(1), one Te(1), and one Te(3) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one W(1), and one Te(2) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one Te(1) and one Te(3) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one W(1) and one Te(2) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Mg(1), one Te(2), and one Te(3) atom.