CsTi5Se8 crystallizes in the monoclinic C2/m space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent Se(1), four equivalent Se(2), and four equivalent Se(3) atoms. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. In the second Ti site, Ti(2) is bonded to one Se(1), two equivalent Se(2), and three equivalent Se(4) atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. In the third Ti site, Ti(3) is bonded to one Se(1), two equivalent Se(4), and three equivalent Se(3) atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Ti(2), one Ti(3), and two equivalent Ti(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one Ti(1), and two equivalent Ti(2) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1) and three equivalent Ti(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent Ti(3) and three equivalent Ti(2) atoms to form distorted edge-sharing SeTi5 square pyramids.
CsTi5Se8 crystallizes in the monoclinic C2/m space group. Cs(1) is bonded in a 10-coordinate geometry to two equivalent Se(1), four equivalent Se(2), and four equivalent Se(3) atoms. Both Cs(1)-Se(1) bond lengths are 3.74 Å. All Cs(1)-Se(2) bond lengths are 3.66 Å. All Cs(1)-Se(3) bond lengths are 3.60 Å. There are three inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles are 48°. Both Ti(1)-Se(2) bond lengths are 2.58 Å. All Ti(1)-Se(1) bond lengths are 2.59 Å. In the second Ti site, Ti(2) is bonded to one Se(1), two equivalent Se(2), and three equivalent Se(4) atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. The Ti(2)-Se(1) bond length is 2.56 Å. Both Ti(2)-Se(2) bond lengths are 2.57 Å. There are two shorter (2.64 Å) and one longer (2.65 Å) Ti(2)-Se(4) bond length. In the third Ti site, Ti(3) is bonded to one Se(1), two equivalent Se(4), and three equivalent Se(3) atoms to form a mixture of corner, edge, and face-sharing TiSe6 octahedra. The corner-sharing octahedral tilt angles range from 47-50°. The Ti(3)-Se(1) bond length is 2.67 Å. Both Ti(3)-Se(4) bond lengths are 2.70 Å. There is one shorter (2.51 Å) and two longer (2.55 Å) Ti(3)-Se(3) bond lengths. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted rectangular see-saw-like geometry to one Cs(1), one Ti(2), one Ti(3), and two equivalent Ti(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one Ti(1), and two equivalent Ti(2) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1) and three equivalent Ti(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent Ti(3) and three equivalent Ti(2) atoms to form distorted edge-sharing SeTi5 square pyramids.