CuTaO3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 6°. In the second Ta site, Ta(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 6°. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. In the second Cu site, Cu(2) is bonded in a linear geometry to two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ta(1), two equivalent Ta(2), and one Cu(1) atom to form distorted edge-sharing OTa3Cu tetrahedra. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ta(1) and one Cu(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Ta(1) and one Ta(2) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ta(1), one Ta(2), and one Cu(2) atom.
CuTaO3 crystallizes in the monoclinic C2/m space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 6°. The Ta(1)-O(1) bond length is 2.29 Å. The Ta(1)-O(2) bond length is 1.83 Å. Both Ta(1)-O(3) bond lengths are 1.97 Å. Both Ta(1)-O(4) bond lengths are 2.06 Å. In the second Ta site, Ta(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form a mixture of distorted corner and edge-sharing TaO6 octahedra. The corner-sharing octahedral tilt angles are 6°. Both Ta(2)-O(1) bond lengths are 2.16 Å. Both Ta(2)-O(3) bond lengths are 1.89 Å. Both Ta(2)-O(4) bond lengths are 2.02 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. The Cu(1)-O(1) bond length is 1.85 Å. The Cu(1)-O(2) bond length is 1.81 Å. In the second Cu site, Cu(2) is bonded in a linear geometry to two equivalent O(4) atoms. Both Cu(2)-O(4) bond lengths are 1.89 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded to one Ta(1), two equivalent Ta(2), and one Cu(1) atom to form distorted edge-sharing OTa3Cu tetrahedra. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ta(1) and one Cu(1) atom. In the third O site, O(3) is bonded in a linear geometry to one Ta(1) and one Ta(2) atom. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to one Ta(1), one Ta(2), and one Cu(2) atom.