NaCu3Ti3NbO12 crystallizes in the trigonal R-3 space group. Na(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form NaO12 cuboctahedra that share faces with two equivalent Nb(1)O6 octahedra and faces with six equivalent Ti(1)O6 octahedra. Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. Nb(1) is bonded to six equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ti(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ti(1), one Nb(1), and one Cu(1) atom.
NaCu3Ti3NbO12 crystallizes in the trigonal R-3 space group. Na(1) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form NaO12 cuboctahedra that share faces with two equivalent Nb(1)O6 octahedra and faces with six equivalent Ti(1)O6 octahedra. All Na(1)-O(1) bond lengths are 2.67 Å. All Na(1)-O(2) bond lengths are 2.66 Å. Ti(1) is bonded to two equivalent O(2) and four equivalent O(1) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Ti(1)O6 octahedra, and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. Both Ti(1)-O(2) bond lengths are 1.98 Å. There are two shorter (1.99 Å) and two longer (2.00 Å) Ti(1)-O(1) bond lengths. Nb(1) is bonded to six equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and faces with two equivalent Na(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles are 40°. All Nb(1)-O(2) bond lengths are 2.01 Å. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(2) atoms. Both Cu(1)-O(1) bond lengths are 1.98 Å. Both Cu(1)-O(2) bond lengths are 1.97 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Na(1), two equivalent Ti(1), and one Cu(1) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Na(1), one Ti(1), one Nb(1), and one Cu(1) atom.