MgCu2(TeO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form MgO4 tetrahedra that share corners with three equivalent Te(1)O6 octahedra and corners with three equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-69°. Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(5) atoms to form TeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra and edges with two equivalent Te(2)O6 octahedra. In the second Te site, Te(2) is bonded to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form distorted TeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra and edges with two equivalent Te(1)O6 octahedra. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to two equivalent Cu(1) and one Te(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Cu(1), one Te(1), and one Te(2) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Cu(1) and one Te(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), two equivalent Cu(1), and one Te(2) atom to form a mixture of distorted edge and corner-sharing OMgCu2Te tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(1), one Te(1), and one Te(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), two equivalent Cu(1), and one Te(1) atom to form a mixture of edge and corner-sharing OMgCu2Te tetrahedra.
MgCu2(TeO4)2 crystallizes in the monoclinic Cm space group. Mg(1) is bonded to one O(4), one O(6), and two equivalent O(5) atoms to form MgO4 tetrahedra that share corners with three equivalent Te(1)O6 octahedra and corners with three equivalent Te(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 51-69°. The Mg(1)-O(4) bond length is 2.00 Å. The Mg(1)-O(6) bond length is 2.25 Å. Both Mg(1)-O(5) bond lengths are 2.02 Å. Cu(1) is bonded in a distorted rectangular see-saw-like geometry to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom. The Cu(1)-O(1) bond length is 2.03 Å. The Cu(1)-O(2) bond length is 2.62 Å. The Cu(1)-O(3) bond length is 1.94 Å. The Cu(1)-O(4) bond length is 1.95 Å. The Cu(1)-O(5) bond length is 2.63 Å. The Cu(1)-O(6) bond length is 2.15 Å. There are two inequivalent Te sites. In the first Te site, Te(1) is bonded to one O(1), one O(6), two equivalent O(2), and two equivalent O(5) atoms to form TeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra and edges with two equivalent Te(2)O6 octahedra. The Te(1)-O(1) bond length is 1.98 Å. The Te(1)-O(6) bond length is 2.02 Å. Both Te(1)-O(2) bond lengths are 2.03 Å. Both Te(1)-O(5) bond lengths are 1.92 Å. In the second Te site, Te(2) is bonded to one O(3), one O(4), two equivalent O(2), and two equivalent O(5) atoms to form distorted TeO6 octahedra that share corners with three equivalent Mg(1)O4 tetrahedra and edges with two equivalent Te(1)O6 octahedra. The Te(2)-O(3) bond length is 2.04 Å. The Te(2)-O(4) bond length is 2.25 Å. Both Te(2)-O(2) bond lengths are 2.00 Å. Both Te(2)-O(5) bond lengths are 2.57 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a trigonal non-coplanar geometry to two equivalent Cu(1) and one Te(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Cu(1), one Te(1), and one Te(2) atom. In the third O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Cu(1) and one Te(2) atom. In the fourth O site, O(4) is bonded to one Mg(1), two equivalent Cu(1), and one Te(2) atom to form a mixture of distorted edge and corner-sharing OMgCu2Te tetrahedra. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Mg(1), one Cu(1), one Te(1), and one Te(2) atom. In the sixth O site, O(6) is bonded to one Mg(1), two equivalent Cu(1), and one Te(1) atom to form a mixture of edge and corner-sharing OMgCu2Te tetrahedra.