Ti2Nb2(CuO4)3 crystallizes in the monoclinic C2/m space group. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-41°. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-42°. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ti(1) and one Cu(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ti(1), one Nb(1), and one Cu(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ti(1), one Nb(1), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one Cu(3) atom.
Ti2Nb2(CuO4)3 crystallizes in the monoclinic C2/m space group. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with four equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 39-41°. Both Ti(1)-O(1) bond lengths are 2.00 Å. Both Ti(1)-O(2) bond lengths are 1.99 Å. Both Ti(1)-O(3) bond lengths are 2.00 Å. Nb(1) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 41-42°. Both Nb(1)-O(2) bond lengths are 2.02 Å. Both Nb(1)-O(3) bond lengths are 2.02 Å. Both Nb(1)-O(4) bond lengths are 2.02 Å. There are three inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a square co-planar geometry to four equivalent O(3) atoms. All Cu(1)-O(3) bond lengths are 1.97 Å. In the second Cu site, Cu(2) is bonded in a square co-planar geometry to four equivalent O(2) atoms. All Cu(2)-O(2) bond lengths are 1.97 Å. In the third Cu site, Cu(3) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Cu(3)-O(1) bond lengths are 1.97 Å. Both Cu(3)-O(4) bond lengths are 1.96 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Ti(1) and one Cu(3) atom. In the second O site, O(2) is bonded in a distorted trigonal planar geometry to one Ti(1), one Nb(1), and one Cu(2) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ti(1), one Nb(1), and one Cu(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one Cu(3) atom.