MgCu2(TeO4)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted MgO6 octahedra that share edges with two equivalent Cu(1)O6 octahedra and edges with four equivalent Te(1)O6 octahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Te(1)O6 octahedra. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. Te(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TeO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cu(1), one Cu(2), and one Te(1) atom to form a mixture of edge and corner-sharing OMgCu2Te tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cu(1) and two equivalent Te(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Te(1) atoms.
MgCu2(TeO4)2 is beta indium sulfide-derived structured and crystallizes in the monoclinic C2/m space group. Mg(1) is bonded to two equivalent O(3) and four equivalent O(1) atoms to form distorted MgO6 octahedra that share edges with two equivalent Cu(1)O6 octahedra and edges with four equivalent Te(1)O6 octahedra. Both Mg(1)-O(3) bond lengths are 2.24 Å. All Mg(1)-O(1) bond lengths are 2.20 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form distorted CuO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra and edges with four equivalent Te(1)O6 octahedra. Both Cu(1)-O(2) bond lengths are 2.53 Å. All Cu(1)-O(1) bond lengths are 2.04 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(1) atoms. All Cu(2)-O(1) bond lengths are 2.14 Å. Te(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TeO6 octahedra that share edges with two equivalent Mg(1)O6 octahedra, edges with two equivalent Cu(1)O6 octahedra, and edges with two equivalent Te(1)O6 octahedra. Both Te(1)-O(1) bond lengths are 2.00 Å. Both Te(1)-O(2) bond lengths are 2.03 Å. Both Te(1)-O(3) bond lengths are 2.06 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded to one Mg(1), one Cu(1), one Cu(2), and one Te(1) atom to form a mixture of edge and corner-sharing OMgCu2Te tetrahedra. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Cu(1) and two equivalent Te(1) atoms. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Mg(1) and two equivalent Te(1) atoms.