MgWTe3O12 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 pentagonal pyramids that share corners with two equivalent Te(2)O6 octahedra, corners with four equivalent W(1)O6 octahedra,  an edgeedge with one Te(3)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-60°. W(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form WO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, corners with four equivalent Mg(1)O6 pentagonal pyramids, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. 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 W(1)O6 octahedra, edges with two equivalent Te(3)O6 octahedra, and edges with two equivalent Mg(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 45°. 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, corners with two equivalent Mg(1)O6 pentagonal pyramids, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. 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 TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra, edges with two equivalent Te(1)O6 octahedra, and  an edgeedge with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 43°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(1), and one Te(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Te(1) and one Te(3) atom. In the third O site, O(3) is bonded in a water-like geometry to one W(1) and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Te(1), and one Te(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one W(1), and one Te(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Te(2) and one Te(3) atom.
MgWTe3O12 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form distorted MgO6 pentagonal pyramids that share corners with two equivalent Te(2)O6 octahedra, corners with four equivalent W(1)O6 octahedra,  an edgeedge with one Te(3)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 36-60°. Both Mg(1)-O(1) bond lengths are 2.26 Å. Both Mg(1)-O(4) bond lengths are 2.24 Å. Both Mg(1)-O(5) bond lengths are 2.02 Å. W(1) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(5) atoms to form WO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, corners with four equivalent Mg(1)O6 pentagonal pyramids, and edges with two equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles are 45°. Both W(1)-O(1) bond lengths are 2.12 Å. Both W(1)-O(3) bond lengths are 1.87 Å. Both W(1)-O(5) bond lengths are 1.94 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 W(1)O6 octahedra, edges with two equivalent Te(3)O6 octahedra, and edges with two equivalent Mg(1)O6 pentagonal pyramids. The corner-sharing octahedral tilt angles are 45°. Both Te(1)-O(1) bond lengths are 1.94 Å. Both Te(1)-O(2) bond lengths are 1.99 Å. Both Te(1)-O(4) bond lengths are 1.99 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, corners with two equivalent Mg(1)O6 pentagonal pyramids, and edges with two equivalent W(1)O6 octahedra. The corner-sharing octahedral tilt angles are 43°. Both Te(2)-O(3) bond lengths are 2.13 Å. Both Te(2)-O(5) bond lengths are 2.30 Å. Both Te(2)-O(6) bond lengths are 2.05 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 TeO6 octahedra that share corners with two equivalent Te(2)O6 octahedra, edges with two equivalent Te(1)O6 octahedra, and  an edgeedge with one Mg(1)O6 pentagonal pyramid. The corner-sharing octahedral tilt angles are 43°. Both Te(3)-O(2) bond lengths are 1.98 Å. Both Te(3)-O(4) bond lengths are 2.07 Å. Both Te(3)-O(6) bond lengths are 1.90 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Mg(1), one W(1), and one Te(1) atom. In the second O site, O(2) is bonded in a water-like geometry to one Te(1) and one Te(3) atom. In the third O site, O(3) is bonded in a water-like geometry to one W(1) and one Te(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal non-coplanar geometry to one Mg(1), one Te(1), and one Te(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Mg(1), one W(1), and one Te(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Te(2) and one Te(3) atom.