MgFe4(TeO6)2 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Te(1)O6 octahedra, corners with two equivalent Te(2)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Fe(4)O6 octahedra, corners with four equivalent Te(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Fe(3)O6 octahedra, corners with four equivalent Te(1)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra,  an edgeedge with one Te(2)O6 octahedra, and edges with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Te(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Te(1)O6 octahedra, and edges with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. In the fourth Fe site, Fe(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Te(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-49°. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form TeO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Te(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Te(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(4), and one Te(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Te(2) atom.
MgFe4(TeO6)2 crystallizes in the monoclinic P2 space group. Mg(1) is bonded to two equivalent O(1) and two equivalent O(4) atoms to form distorted MgO4 tetrahedra that share corners with two equivalent Te(1)O6 octahedra, corners with two equivalent Te(2)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles are 60°. Both Mg(1)-O(1) bond lengths are 1.95 Å. Both Mg(1)-O(4) bond lengths are 1.94 Å. There are four inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Fe(4)O6 octahedra, corners with four equivalent Te(2)O6 octahedra,  an edgeedge with one Fe(3)O6 octahedra, and  an edgeedge with one Te(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. Both Fe(1)-O(2) bond lengths are 2.12 Å. Both Fe(1)-O(3) bond lengths are 2.04 Å. Both Fe(1)-O(6) bond lengths are 2.02 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Fe(3)O6 octahedra, corners with four equivalent Te(1)O6 octahedra,  an edgeedge with one Fe(4)O6 octahedra,  an edgeedge with one Te(2)O6 octahedra, and edges with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. Both Fe(2)-O(1) bond lengths are 2.20 Å. Both Fe(2)-O(4) bond lengths are 2.13 Å. Both Fe(2)-O(5) bond lengths are 2.06 Å. In the third Fe site, Fe(3) is bonded to two equivalent O(1), two equivalent O(4), and two equivalent O(6) atoms to form FeO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Te(2)O6 octahedra,  an edgeedge with one Fe(1)O6 octahedra,  an edgeedge with one Te(1)O6 octahedra, and edges with two equivalent Mg(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 46-55°. Both Fe(3)-O(1) bond lengths are 2.12 Å. Both Fe(3)-O(4) bond lengths are 2.17 Å. Both Fe(3)-O(6) bond lengths are 2.08 Å. In the fourth Fe site, Fe(4) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms to form FeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Te(1)O6 octahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-49°. Both Fe(4)-O(2) bond lengths are 1.98 Å. Both Fe(4)-O(3) bond lengths are 2.08 Å. Both Fe(4)-O(5) bond lengths are 2.02 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form TeO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, corners with four equivalent Fe(4)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Fe(1)O6 octahedra, and  an edgeedge with one Fe(3)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-50°. Both Te(1)-O(3) bond lengths are 1.95 Å. Both Te(1)-O(4) bond lengths are 1.99 Å. Both Te(1)-O(5) bond lengths are 1.99 Å. In the second Te site, Te(2) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(6) atoms to form TeO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, corners with four equivalent Fe(3)O6 octahedra, corners with two equivalent Mg(1)O4 tetrahedra,  an edgeedge with one Fe(2)O6 octahedra, and  an edgeedge with one Fe(4)O6 octahedra. The corner-sharing octahedral tilt angles range from 46-51°. Both Te(2)-O(1) bond lengths are 1.98 Å. Both Te(2)-O(2) bond lengths are 1.95 Å. Both Te(2)-O(6) bond lengths are 1.97 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Te(2) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Te(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Fe(1), one Fe(4), and one Te(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Mg(1), one Fe(2), one Fe(3), and one Te(1) atom. In the fifth O site, O(5) is bonded in a distorted T-shaped geometry to one Fe(2), one Fe(4), and one Te(1) atom. In the sixth O site, O(6) is bonded in a distorted T-shaped geometry to one Fe(1), one Fe(3), and one Te(2) atom.