Na2Cu2TeO6 crystallizes in the monoclinic C2/m space group. Na(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted NaO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, edges with two equivalent Te(1)O6 octahedra, and edges with three equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Te(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TeO6 octahedra that share corners with four equivalent Na(1)O6 octahedra and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Cu(1), and one Te(1) atom to form a mixture of distorted corner and edge-sharing ONa2Cu2Te trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Cu(1), and one Te(1) atom.
Na2Cu2TeO6 crystallizes in the monoclinic C2/m space group. Na(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted NaO6 octahedra that share corners with two equivalent Te(1)O6 octahedra, edges with two equivalent Te(1)O6 octahedra, and edges with three equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. Both Na(1)-O(1) bond lengths are 2.53 Å. There are two shorter (2.32 Å) and two longer (2.41 Å) Na(1)-O(2) bond lengths. Cu(1) is bonded in a distorted rectangular see-saw-like geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 2.02 Å. Both Cu(1)-O(2) bond lengths are 1.99 Å. Te(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form TeO6 octahedra that share corners with four equivalent Na(1)O6 octahedra and edges with four equivalent Na(1)O6 octahedra. The corner-sharing octahedral tilt angles are 15°. Both Te(1)-O(1) bond lengths are 2.03 Å. All Te(1)-O(2) bond lengths are 1.95 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(1), two equivalent Cu(1), and one Te(1) atom to form a mixture of distorted corner and edge-sharing ONa2Cu2Te trigonal bipyramids. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Cu(1), and one Te(1) atom.