TiNb3O2Cl7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2), two equivalent Cl(5), and two equivalent Cl(7) atoms to form distorted TiCl4O2 octahedra that share corners with two equivalent Nb(1)Cl4O square pyramids and edges with two equivalent Ti(2)Cl4O2 octahedra. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent Cl(5), and two equivalent Cl(7) atoms to form TiCl4O2 octahedra that share corners with two equivalent Nb(2)Cl4O square pyramids and edges with two equivalent Ti(1)Cl4O2 octahedra. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one Cl(1), one Cl(2), one Cl(3), and one Cl(4) atom to form distorted NbCl4O square pyramids that share  a cornercorner with one Ti(1)Cl4O2 octahedra,  a cornercorner with one Nb(1)Cl4O square pyramid, and corners with two equivalent Nb(2)Cl4O square pyramids. The corner-sharing octahedral tilt angles are 26°. In the second Nb site, Nb(2) is bonded to one O(1), one Cl(1), one Cl(3), one Cl(6), and one Cl(8) atom to form distorted NbCl4O square pyramids that share  a cornercorner with one Ti(2)Cl4O2 octahedra,  a cornercorner with one Nb(2)Cl4O square pyramid, and corners with two equivalent Nb(1)Cl4O square pyramids. The corner-sharing octahedral tilt angles are 20°. In the third Nb site, Nb(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one Cl(4), one Cl(5), and one Cl(6) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ti(2), one Nb(2), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ti(1), one Nb(1), and one Nb(3) atom. There are eight inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a distorted L-shaped geometry to one Nb(1) and one Nb(2) atom. In the second Cl site, Cl(2) is bonded in a bent 120 degrees geometry to two equivalent Nb(1) atoms. In the third Cl site, Cl(3) is bonded in a distorted L-shaped geometry to one Nb(1) and one Nb(2) atom. In the fourth Cl site, Cl(4) is bonded in a 2-coordinate geometry to one Nb(1) and one Nb(3) atom. In the fifth Cl site, Cl(5) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Nb(3) atom. In the sixth Cl site, Cl(6) is bonded in a distorted L-shaped geometry to one Nb(2) and one Nb(3) atom. In the seventh Cl site, Cl(7) is bonded in an L-shaped geometry to one Ti(1) and one Ti(2) atom. In the eighth Cl site, Cl(8) is bonded in a linear geometry to two equivalent Nb(2) atoms.
TiNb3O2Cl7 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent O(2), two equivalent Cl(5), and two equivalent Cl(7) atoms to form distorted TiCl4O2 octahedra that share corners with two equivalent Nb(1)Cl4O square pyramids and edges with two equivalent Ti(2)Cl4O2 octahedra. Both Ti(1)-O(2) bond lengths are 1.86 Å. Both Ti(1)-Cl(5) bond lengths are 2.59 Å. Both Ti(1)-Cl(7) bond lengths are 2.44 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(1), two equivalent Cl(5), and two equivalent Cl(7) atoms to form TiCl4O2 octahedra that share corners with two equivalent Nb(2)Cl4O square pyramids and edges with two equivalent Ti(1)Cl4O2 octahedra. Both Ti(2)-O(1) bond lengths are 2.01 Å. Both Ti(2)-Cl(5) bond lengths are 2.47 Å. Both Ti(2)-Cl(7) bond lengths are 2.44 Å. There are three inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(2), one Cl(1), one Cl(2), one Cl(3), and one Cl(4) atom to form distorted NbCl4O square pyramids that share  a cornercorner with one Ti(1)Cl4O2 octahedra,  a cornercorner with one Nb(1)Cl4O square pyramid, and corners with two equivalent Nb(2)Cl4O square pyramids. The corner-sharing octahedral tilt angles are 26°. The Nb(1)-O(2) bond length is 2.04 Å. The Nb(1)-Cl(1) bond length is 2.47 Å. The Nb(1)-Cl(2) bond length is 2.63 Å. The Nb(1)-Cl(3) bond length is 2.44 Å. The Nb(1)-Cl(4) bond length is 2.49 Å. In the second Nb site, Nb(2) is bonded to one O(1), one Cl(1), one Cl(3), one Cl(6), and one Cl(8) atom to form distorted NbCl4O square pyramids that share  a cornercorner with one Ti(2)Cl4O2 octahedra,  a cornercorner with one Nb(2)Cl4O square pyramid, and corners with two equivalent Nb(1)Cl4O square pyramids. The corner-sharing octahedral tilt angles are 20°. The Nb(2)-O(1) bond length is 2.06 Å. The Nb(2)-Cl(1) bond length is 2.46 Å. The Nb(2)-Cl(3) bond length is 2.45 Å. The Nb(2)-Cl(6) bond length is 2.51 Å. The Nb(2)-Cl(8) bond length is 2.65 Å. In the third Nb site, Nb(3) is bonded in a 5-coordinate geometry to one O(1), one O(2), one Cl(4), one Cl(5), and one Cl(6) atom. The Nb(3)-O(1) bond length is 2.09 Å. The Nb(3)-O(2) bond length is 2.10 Å. The Nb(3)-Cl(4) bond length is 2.49 Å. The Nb(3)-Cl(5) bond length is 2.67 Å. The Nb(3)-Cl(6) bond length is 2.48 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted T-shaped geometry to one Ti(2), one Nb(2), and one Nb(3) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Ti(1), one Nb(1), and one Nb(3) atom. There are eight inequivalent Cl sites. In the first Cl site, Cl(1) is bonded in a distorted L-shaped geometry to one Nb(1) and one Nb(2) atom. In the second Cl site, Cl(2) is bonded in a bent 120 degrees geometry to two equivalent Nb(1) atoms. In the third Cl site, Cl(3) is bonded in a distorted L-shaped geometry to one Nb(1) and one Nb(2) atom. In the fourth Cl site, Cl(4) is bonded in a 2-coordinate geometry to one Nb(1) and one Nb(3) atom. In the fifth Cl site, Cl(5) is bonded in a distorted T-shaped geometry to one Ti(1), one Ti(2), and one Nb(3) atom. In the sixth Cl site, Cl(6) is bonded in a distorted L-shaped geometry to one Nb(2) and one Nb(3) atom. In the seventh Cl site, Cl(7) is bonded in an L-shaped geometry to one Ti(1) and one Ti(2) atom. In the eighth Cl site, Cl(8) is bonded in a linear geometry to two equivalent Nb(2) atoms.