Ti4O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form a mixture of distorted edge, corner, and face-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 43-55°. In the second Ti site, Ti(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form a mixture of distorted edge, corner, and face-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 44-61°. In the fourth Ti site, Ti(4) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ti(3) and two equivalent Ti(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(3) atoms. In the fourth O site, O(4) is bonded to one Ti(1), one Ti(2), one Ti(3), and one Ti(4) atom to form distorted edge-sharing OTi4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(1), one Ti(4), and two equivalent Ti(2) atoms to form a mixture of edge and corner-sharing OTi4 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms to form a mixture of edge and corner-sharing OTi4 trigonal pyramids.
Ti4O7 crystallizes in the triclinic P-1 space group. There are four inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(7) atoms to form a mixture of distorted edge, corner, and face-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 43-55°. The Ti(1)-O(2) bond length is 1.92 Å. The Ti(1)-O(4) bond length is 2.13 Å. The Ti(1)-O(5) bond length is 2.01 Å. The Ti(1)-O(6) bond length is 1.87 Å. There is one shorter (1.99 Å) and one longer (2.17 Å) Ti(1)-O(7) bond length. In the second Ti site, Ti(2) is bonded to one O(3), one O(4), one O(6), one O(7), and two equivalent O(5) atoms to form a mixture of distorted edge, corner, and face-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 44-55°. The Ti(2)-O(3) bond length is 1.86 Å. The Ti(2)-O(4) bond length is 2.06 Å. The Ti(2)-O(6) bond length is 1.93 Å. The Ti(2)-O(7) bond length is 2.03 Å. There is one shorter (1.98 Å) and one longer (2.15 Å) Ti(2)-O(5) bond length. In the third Ti site, Ti(3) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(3) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 44-61°. The Ti(3)-O(1) bond length is 1.92 Å. The Ti(3)-O(2) bond length is 2.02 Å. The Ti(3)-O(4) bond length is 2.06 Å. The Ti(3)-O(7) bond length is 2.08 Å. There is one shorter (1.97 Å) and one longer (2.00 Å) Ti(3)-O(3) bond length. In the fourth Ti site, Ti(4) is bonded to one O(2), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form a mixture of edge and corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. The Ti(4)-O(2) bond length is 1.94 Å. The Ti(4)-O(4) bond length is 2.05 Å. The Ti(4)-O(5) bond length is 2.07 Å. The Ti(4)-O(6) bond length is 2.10 Å. There is one shorter (1.95 Å) and one longer (1.97 Å) Ti(4)-O(1) bond length. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ti(3) and two equivalent Ti(4) atoms. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ti(1), one Ti(3), and one Ti(4) atom. In the third O site, O(3) is bonded in a distorted T-shaped geometry to one Ti(2) and two equivalent Ti(3) atoms. In the fourth O site, O(4) is bonded to one Ti(1), one Ti(2), one Ti(3), and one Ti(4) atom to form distorted edge-sharing OTi4 trigonal pyramids. In the fifth O site, O(5) is bonded to one Ti(1), one Ti(4), and two equivalent Ti(2) atoms to form a mixture of edge and corner-sharing OTi4 trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ti(1), one Ti(2), and one Ti(4) atom. In the seventh O site, O(7) is bonded to one Ti(2), one Ti(3), and two equivalent Ti(1) atoms to form a mixture of edge and corner-sharing OTi4 trigonal pyramids.