Ti3NbO8 is Rutile-derived structured and crystallizes in the hexagonal P6_3mc space group. Ti(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. Nb(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with three equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. 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 Nb(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ti(1) and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to three equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to three equivalent Ti(1) atoms.
Ti3NbO8 is Rutile-derived structured and crystallizes in the hexagonal P6_3mc space group. Ti(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form TiO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra,  an edgeedge with one Nb(1)O6 octahedra, and edges with four equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. The Ti(1)-O(3) bond length is 1.98 Å. The Ti(1)-O(4) bond length is 1.96 Å. Both Ti(1)-O(1) bond lengths are 2.05 Å. Both Ti(1)-O(2) bond lengths are 1.98 Å. Nb(1) is bonded to three equivalent O(1) and three equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Ti(1)O6 octahedra and edges with three equivalent Ti(1)O6 octahedra. The corner-sharing octahedral tilt angles are 50°. All Nb(1)-O(1) bond lengths are 1.99 Å. All Nb(1)-O(2) bond lengths are 2.09 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 Nb(1) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ti(1) and one Nb(1) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to three equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a trigonal non-coplanar geometry to three equivalent Ti(1) atoms.