Cs2AgI3 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to two equivalent I(1), two equivalent I(3), and three equivalent I(2) atoms. In the second Cs site, Cs(2) is bonded to two equivalent I(2), two equivalent I(3), and three equivalent I(1) atoms to form distorted CsI7 pentagonal bipyramids that share corners with two equivalent Cs(2)I7 pentagonal bipyramids,  a cornercorner with one Ag(1)I4 tetrahedra, edges with four equivalent Cs(2)I7 pentagonal bipyramids, and edges with four equivalent Ag(1)I4 tetrahedra. Ag(1) is bonded to one I(1), one I(2), and two equivalent I(3) atoms to form AgI4 tetrahedra that share  a cornercorner with one Cs(2)I7 pentagonal bipyramid, corners with two equivalent Ag(1)I4 tetrahedra, and edges with four equivalent Cs(2)I7 pentagonal bipyramids. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Cs(1), three equivalent Cs(2), and one Ag(1) atom to form distorted ICs5Ag octahedra that share corners with five equivalent I(3)Cs4Ag2 octahedra, corners with eight equivalent I(2)Cs5Ag octahedra,  an edgeedge with one I(2)Cs5Ag octahedra, edges with two equivalent I(3)Cs4Ag2 octahedra, edges with four equivalent I(1)Cs5Ag octahedra,  a faceface with one I(3)Cs4Ag2 octahedra, and  a faceface with one I(2)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 27-61°. In the second I site, I(2) is bonded to two equivalent Cs(2), three equivalent Cs(1), and one Ag(1) atom to form distorted ICs5Ag octahedra that share corners with two equivalent I(3)Cs4Ag2 octahedra, corners with eight equivalent I(1)Cs5Ag octahedra,  an edgeedge with one I(1)Cs5Ag octahedra, edges with four equivalent I(2)Cs5Ag octahedra, edges with five equivalent I(3)Cs4Ag2 octahedra, and  a faceface with one I(1)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 17-56°. In the third I site, I(3) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Ag(1) atoms to form distorted ICs4Ag2 octahedra that share corners with two equivalent I(3)Cs4Ag2 octahedra, corners with two equivalent I(2)Cs5Ag octahedra, corners with five equivalent I(1)Cs5Ag octahedra, edges with two equivalent I(3)Cs4Ag2 octahedra, edges with two equivalent I(1)Cs5Ag octahedra, edges with five equivalent I(2)Cs5Ag octahedra, and  a faceface with one I(1)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 17-61°.
Cs2AgI3 crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 7-coordinate geometry to two equivalent I(1), two equivalent I(3), and three equivalent I(2) atoms. Both Cs(1)-I(1) bond lengths are 3.90 Å. Both Cs(1)-I(3) bond lengths are 3.99 Å. There are two shorter (3.88 Å) and one longer (3.95 Å) Cs(1)-I(2) bond length. In the second Cs site, Cs(2) is bonded to two equivalent I(2), two equivalent I(3), and three equivalent I(1) atoms to form distorted CsI7 pentagonal bipyramids that share corners with two equivalent Cs(2)I7 pentagonal bipyramids,  a cornercorner with one Ag(1)I4 tetrahedra, edges with four equivalent Cs(2)I7 pentagonal bipyramids, and edges with four equivalent Ag(1)I4 tetrahedra. Both Cs(2)-I(2) bond lengths are 3.87 Å. There is one shorter (3.91 Å) and one longer (3.92 Å) Cs(2)-I(3) bond length. There are two shorter (3.85 Å) and one longer (3.93 Å) Cs(2)-I(1) bond length. Ag(1) is bonded to one I(1), one I(2), and two equivalent I(3) atoms to form AgI4 tetrahedra that share  a cornercorner with one Cs(2)I7 pentagonal bipyramid, corners with two equivalent Ag(1)I4 tetrahedra, and edges with four equivalent Cs(2)I7 pentagonal bipyramids. The Ag(1)-I(1) bond length is 2.85 Å. The Ag(1)-I(2) bond length is 2.86 Å. Both Ag(1)-I(3) bond lengths are 2.92 Å. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Cs(1), three equivalent Cs(2), and one Ag(1) atom to form distorted ICs5Ag octahedra that share corners with five equivalent I(3)Cs4Ag2 octahedra, corners with eight equivalent I(2)Cs5Ag octahedra,  an edgeedge with one I(2)Cs5Ag octahedra, edges with two equivalent I(3)Cs4Ag2 octahedra, edges with four equivalent I(1)Cs5Ag octahedra,  a faceface with one I(3)Cs4Ag2 octahedra, and  a faceface with one I(2)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 27-61°. In the second I site, I(2) is bonded to two equivalent Cs(2), three equivalent Cs(1), and one Ag(1) atom to form distorted ICs5Ag octahedra that share corners with two equivalent I(3)Cs4Ag2 octahedra, corners with eight equivalent I(1)Cs5Ag octahedra,  an edgeedge with one I(1)Cs5Ag octahedra, edges with four equivalent I(2)Cs5Ag octahedra, edges with five equivalent I(3)Cs4Ag2 octahedra, and  a faceface with one I(1)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 17-56°. In the third I site, I(3) is bonded to two equivalent Cs(1), two equivalent Cs(2), and two equivalent Ag(1) atoms to form distorted ICs4Ag2 octahedra that share corners with two equivalent I(3)Cs4Ag2 octahedra, corners with two equivalent I(2)Cs5Ag octahedra, corners with five equivalent I(1)Cs5Ag octahedra, edges with two equivalent I(3)Cs4Ag2 octahedra, edges with two equivalent I(1)Cs5Ag octahedra, edges with five equivalent I(2)Cs5Ag octahedra, and  a faceface with one I(1)Cs5Ag octahedra. The corner-sharing octahedral tilt angles range from 17-61°.