Ti9O10 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. In the second Ti site, Ti(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form TiO5 square pyramids that share  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Ti(2)O5 square pyramid,  an edgeedge with one Ti(4)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with two equivalent Ti(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 6-8°. In the third Ti site, Ti(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O5 square pyramids, edges with three equivalent Ti(3)O6 octahedra, edges with three equivalent Ti(4)O6 octahedra, and edges with four equivalent Ti(2)O5 square pyramids. In the fourth Ti site, Ti(4) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O5 square pyramids, edges with six equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(2)O5 square pyramids. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Ti(1) and two equivalent Ti(2) atoms. In the second O site, O(2) is bonded to one Ti(4), two equivalent Ti(2), and two equivalent Ti(3) atoms to form a mixture of corner and edge-sharing OTi5 square pyramids. In the third O site, O(3) is bonded to one Ti(4), two equivalent Ti(2), and two equivalent Ti(3) atoms to form a mixture of corner and edge-sharing OTi5 square pyramids.
Ti9O10 crystallizes in the monoclinic C2/m space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a rectangular see-saw-like geometry to four equivalent O(1) atoms. There are two shorter (2.00 Å) and two longer (2.11 Å) Ti(1)-O(1) bond lengths. In the second Ti site, Ti(2) is bonded to one O(3), two equivalent O(1), and two equivalent O(2) atoms to form TiO5 square pyramids that share  a cornercorner with one Ti(4)O6 octahedra, corners with two equivalent Ti(3)O6 octahedra,  a cornercorner with one Ti(2)O5 square pyramid,  an edgeedge with one Ti(4)O6 octahedra, edges with two equivalent Ti(3)O6 octahedra, and edges with two equivalent Ti(2)O5 square pyramids. The corner-sharing octahedral tilt angles range from 6-8°. The Ti(2)-O(3) bond length is 2.08 Å. There is one shorter (1.96 Å) and one longer (2.07 Å) Ti(2)-O(1) bond length. There is one shorter (2.13 Å) and one longer (2.14 Å) Ti(2)-O(2) bond length. In the third Ti site, Ti(3) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O5 square pyramids, edges with three equivalent Ti(3)O6 octahedra, edges with three equivalent Ti(4)O6 octahedra, and edges with four equivalent Ti(2)O5 square pyramids. Both Ti(3)-O(3) bond lengths are 2.06 Å. There are two shorter (2.07 Å) and two longer (2.15 Å) Ti(3)-O(2) bond lengths. In the fourth Ti site, Ti(4) is bonded to two equivalent O(3) and four equivalent O(2) atoms to form TiO6 octahedra that share corners with four equivalent Ti(2)O5 square pyramids, edges with six equivalent Ti(3)O6 octahedra, and edges with four equivalent Ti(2)O5 square pyramids. Both Ti(4)-O(3) bond lengths are 2.16 Å. All Ti(4)-O(2) bond lengths are 2.09 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to two equivalent Ti(1) and two equivalent Ti(2) atoms. In the second O site, O(2) is bonded to one Ti(4), two equivalent Ti(2), and two equivalent Ti(3) atoms to form a mixture of corner and edge-sharing OTi5 square pyramids. In the third O site, O(3) is bonded to one Ti(4), two equivalent Ti(2), and two equivalent Ti(3) atoms to form a mixture of corner and edge-sharing OTi5 square pyramids.