Ti9Se2 crystallizes in the orthorhombic Pbam space group. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 4-coordinate geometry to four equivalent Se(1) atoms. In the second Ti site, Ti(2) is bonded in a distorted L-shaped geometry to two equivalent Ti(5) and two equivalent Se(1) atoms. In the third Ti site, Ti(3) is bonded in a distorted L-shaped geometry to one Ti(5) and two equivalent Se(1) atoms. In the fourth Ti site, Ti(4) is bonded in a distorted single-bond geometry to two equivalent Ti(5) and one Se(1) atom. In the fifth Ti site, Ti(5) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Ti(2), and four equivalent Ti(4) atoms. Se(1) is bonded in a 9-coordinate geometry to one Ti(4), two equivalent Ti(2), two equivalent Ti(3), and four equivalent Ti(1) atoms.
Ti9Se2 crystallizes in the orthorhombic Pbam space group. There are five inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 4-coordinate geometry to four equivalent Se(1) atoms. There are two shorter (2.65 Å) and two longer (2.68 Å) Ti(1)-Se(1) bond lengths. In the second Ti site, Ti(2) is bonded in a distorted L-shaped geometry to two equivalent Ti(5) and two equivalent Se(1) atoms. Both Ti(2)-Ti(5) bond lengths are 2.84 Å. There is one shorter (2.64 Å) and one longer (2.77 Å) Ti(2)-Se(1) bond length. In the third Ti site, Ti(3) is bonded in a distorted L-shaped geometry to one Ti(5) and two equivalent Se(1) atoms. The Ti(3)-Ti(5) bond length is 2.91 Å. Both Ti(3)-Se(1) bond lengths are 2.61 Å. In the fourth Ti site, Ti(4) is bonded in a distorted single-bond geometry to two equivalent Ti(5) and one Se(1) atom. Both Ti(4)-Ti(5) bond lengths are 2.71 Å. The Ti(4)-Se(1) bond length is 2.72 Å. In the fifth Ti site, Ti(5) is bonded in a 10-coordinate geometry to two equivalent Ti(3), four equivalent Ti(2), and four equivalent Ti(4) atoms. Se(1) is bonded in a 9-coordinate geometry to one Ti(4), two equivalent Ti(2), two equivalent Ti(3), and four equivalent Ti(1) atoms.