Ti2C2O9 crystallizes in the orthorhombic Cmce space group. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to two equivalent O(1) atoms. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) atoms. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ti(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ti(1) and one C(2) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded in a single-bond geometry to one Ti(1) atom.
Ti2C2O9 crystallizes in the orthorhombic Cmce space group. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form distorted corner-sharing TiO6 octahedra. The corner-sharing octahedral tilt angles range from 0-14°. The Ti(1)-O(1) bond length is 2.17 Å. The Ti(1)-O(2) bond length is 2.17 Å. The Ti(1)-O(3) bond length is 1.85 Å. The Ti(1)-O(4) bond length is 1.86 Å. The Ti(1)-O(5) bond length is 1.83 Å. The Ti(1)-O(6) bond length is 2.06 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to two equivalent O(1) atoms. Both C(1)-O(1) bond lengths are 1.26 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) atoms. Both C(2)-O(2) bond lengths are 1.26 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ti(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ti(1) and one C(2) atom. In the third O site, O(3) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fourth O site, O(4) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the fifth O site, O(5) is bonded in a linear geometry to two equivalent Ti(1) atoms. In the sixth O site, O(6) is bonded in a single-bond geometry to one Ti(1) atom.