CsInSe2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), one Se(5), two equivalent Se(2), and three equivalent Se(4) atoms. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), one Se(4), two equivalent Se(2), and three equivalent Se(5) atoms. There are two inequivalent In sites. In the first In site, In(1) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form corner-sharing InSe4 tetrahedra. In the second In site, In(2) is bonded to one Se(2), one Se(3), one Se(4), and one Se(5) atom to form corner-sharing InSe4 tetrahedra. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent In(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), one In(1), and one In(2) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent In(2) atoms. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one Cs(2), three equivalent Cs(1), one In(1), and one In(2) atom. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to one Cs(1), three equivalent Cs(2), one In(1), and one In(2) atom.
CsInSe2 crystallizes in the monoclinic C2/c space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), one Se(5), two equivalent Se(2), and three equivalent Se(4) atoms. The Cs(1)-Se(1) bond length is 3.73 Å. The Cs(1)-Se(3) bond length is 3.72 Å. The Cs(1)-Se(5) bond length is 3.65 Å. Both Cs(1)-Se(2) bond lengths are 3.72 Å. There are a spread of Cs(1)-Se(4) bond distances ranging from 3.66-4.19 Å. In the second Cs site, Cs(2) is bonded in a 8-coordinate geometry to one Se(1), one Se(3), one Se(4), two equivalent Se(2), and three equivalent Se(5) atoms. The Cs(2)-Se(1) bond length is 3.78 Å. The Cs(2)-Se(3) bond length is 3.79 Å. The Cs(2)-Se(4) bond length is 3.72 Å. There is one shorter (3.78 Å) and one longer (3.79 Å) Cs(2)-Se(2) bond length. There are a spread of Cs(2)-Se(5) bond distances ranging from 3.69-4.20 Å. There are two inequivalent In sites. In the first In site, In(1) is bonded to one Se(1), one Se(2), one Se(4), and one Se(5) atom to form corner-sharing InSe4 tetrahedra. The In(1)-Se(1) bond length is 2.59 Å. The In(1)-Se(2) bond length is 2.59 Å. The In(1)-Se(4) bond length is 2.62 Å. The In(1)-Se(5) bond length is 2.61 Å. In the second In site, In(2) is bonded to one Se(2), one Se(3), one Se(4), and one Se(5) atom to form corner-sharing InSe4 tetrahedra. The In(2)-Se(2) bond length is 2.59 Å. The In(2)-Se(3) bond length is 2.59 Å. The In(2)-Se(4) bond length is 2.61 Å. The In(2)-Se(5) bond length is 2.61 Å. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent In(1) atoms. In the second Se site, Se(2) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), one In(1), and one In(2) atom. In the third Se site, Se(3) is bonded in a 6-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and two equivalent In(2) atoms. In the fourth Se site, Se(4) is bonded in a 6-coordinate geometry to one Cs(2), three equivalent Cs(1), one In(1), and one In(2) atom. In the fifth Se site, Se(5) is bonded in a 6-coordinate geometry to one Cs(1), three equivalent Cs(2), one In(1), and one In(2) atom.