Cs2CoI4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to two equivalent I(2), three equivalent I(1), and four equivalent I(3) atoms. In the second Cs site, Cs(2) is bonded in a 7-coordinate geometry to one I(1), two equivalent I(2), and four equivalent I(3) atoms. Co(1) is bonded in a tetrahedral geometry to one I(1), one I(2), and two equivalent I(3) atoms. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 1-coordinate geometry to one Cs(2), three equivalent Cs(1), and one Co(1) atom. In the second I site, I(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one Co(1) atom. In the third I site, I(3) is bonded in a distorted single-bond geometry to two equivalent Cs(1), two equivalent Cs(2), and one Co(1) atom.
Cs2CoI4 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to two equivalent I(2), three equivalent I(1), and four equivalent I(3) atoms. There is one shorter (3.87 Å) and one longer (4.04 Å) Cs(1)-I(2) bond length. There is one shorter (3.91 Å) and two longer (4.28 Å) Cs(1)-I(1) bond lengths. There are two shorter (3.98 Å) and two longer (4.04 Å) Cs(1)-I(3) bond lengths. In the second Cs site, Cs(2) is bonded in a 7-coordinate geometry to one I(1), two equivalent I(2), and four equivalent I(3) atoms. The Cs(2)-I(1) bond length is 4.19 Å. Both Cs(2)-I(2) bond lengths are 4.23 Å. There are two shorter (4.05 Å) and two longer (4.27 Å) Cs(2)-I(3) bond lengths. Co(1) is bonded in a tetrahedral geometry to one I(1), one I(2), and two equivalent I(3) atoms. The Co(1)-I(1) bond length is 2.60 Å. The Co(1)-I(2) bond length is 2.59 Å. Both Co(1)-I(3) bond lengths are 2.58 Å. There are three inequivalent I sites. In the first I site, I(1) is bonded in a 1-coordinate geometry to one Cs(2), three equivalent Cs(1), and one Co(1) atom. In the second I site, I(2) is bonded in a 5-coordinate geometry to two equivalent Cs(1), two equivalent Cs(2), and one Co(1) atom. In the third I site, I(3) is bonded in a distorted single-bond geometry to two equivalent Cs(1), two equivalent Cs(2), and one Co(1) atom.