CsV5Se8 crystallizes in the triclinic P-1 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 V sites. In the first V site, V(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing VSe6 octahedra. The corner-sharing octahedral tilt angles are 50°. In the second V site, V(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 VSe6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. In the third V site, V(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 VSe6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Cs(1), one V(2), one V(3), and two equivalent V(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one V(1), and two equivalent V(2) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1) and three equivalent V(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent V(3) and three equivalent V(2) atoms to form distorted edge-sharing SeV5 trigonal bipyramids.
CsV5Se8 crystallizes in the triclinic P-1 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 3.63 Å. All Cs(1)-Se(2) bond lengths are 3.65 Å. There are two shorter (3.66 Å) and two longer (3.67 Å) Cs(1)-Se(3) bond lengths. There are three inequivalent V sites. In the first V site, V(1) is bonded to two equivalent Se(2) and four equivalent Se(1) atoms to form a mixture of corner and edge-sharing VSe6 octahedra. The corner-sharing octahedral tilt angles are 50°. Both V(1)-Se(2) bond lengths are 2.54 Å. There are two shorter (2.57 Å) and two longer (2.58 Å) V(1)-Se(1) bond lengths. In the second V site, V(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 VSe6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. The V(2)-Se(1) bond length is 2.45 Å. There is one shorter (2.49 Å) and one longer (2.50 Å) V(2)-Se(2) bond length. There are two shorter (2.65 Å) and one longer (2.71 Å) V(2)-Se(4) bond length. In the third V site, V(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 VSe6 octahedra. The corner-sharing octahedral tilt angles range from 50-52°. The V(3)-Se(1) bond length is 2.64 Å. There is one shorter (2.68 Å) and one longer (2.69 Å) V(3)-Se(4) bond length. There are a spread of V(3)-Se(3) bond distances ranging from 2.52-2.54 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a 5-coordinate geometry to one Cs(1), one V(2), one V(3), and two equivalent V(1) atoms. In the second Se site, Se(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), one V(1), and two equivalent V(2) atoms. In the third Se site, Se(3) is bonded in a 5-coordinate geometry to two equivalent Cs(1) and three equivalent V(3) atoms. In the fourth Se site, Se(4) is bonded to two equivalent V(3) and three equivalent V(2) atoms to form distorted edge-sharing SeV5 trigonal bipyramids.