CsSrI3 crystallizes in the orthorhombic Cmcm space group. Cs(1) is bonded in a 8-coordinate geometry to two equivalent I(2) and six equivalent I(1) atoms. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form a mixture of corner and edge-sharing SrI6 octahedra. The corner-sharing octahedral tilt angles are 38°. There are two inequivalent I sites. In the first I site, I(1) is bonded in a 5-coordinate geometry to three equivalent Cs(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded in a 4-coordinate geometry to two equivalent Cs(1) and two equivalent Sr(1) atoms.
CsSrI3 crystallizes in the orthorhombic Cmcm space group. Cs(1) is bonded in a 8-coordinate geometry to two equivalent I(2) and six equivalent I(1) atoms. Both Cs(1)-I(2) bond lengths are 3.85 Å. There are four shorter (3.97 Å) and two longer (4.16 Å) Cs(1)-I(1) bond lengths. Sr(1) is bonded to two equivalent I(2) and four equivalent I(1) atoms to form a mixture of corner and edge-sharing SrI6 octahedra. The corner-sharing octahedral tilt angles are 38°. Both Sr(1)-I(2) bond lengths are 3.26 Å. All Sr(1)-I(1) bond lengths are 3.32 Å. There are two inequivalent I sites. In the first I site, I(1) is bonded in a 5-coordinate geometry to three equivalent Cs(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded in a 4-coordinate geometry to two equivalent Cs(1) and two equivalent Sr(1) atoms.