CsBaI3 crystallizes in the orthorhombic Pnma space group. Cs(1) is bonded in a 9-coordinate geometry to two equivalent I(2), three equivalent I(1), and four equivalent I(3) atoms. Ba(1) is bonded to one I(3), two equivalent I(1), and three equivalent I(2) atoms to form edge-sharing BaI6 octahedra. There are three 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 Ba(1) atoms. In the second I site, I(2) is bonded to two equivalent Cs(1) and three equivalent Ba(1) atoms to form distorted ICs2Ba3 trigonal bipyramids that share corners with three equivalent I(3)Cs4Ba square pyramids, corners with four equivalent I(2)Cs2Ba3 trigonal bipyramids, edges with four equivalent I(3)Cs4Ba square pyramids, and edges with two equivalent I(2)Cs2Ba3 trigonal bipyramids. In the third I site, I(3) is bonded to four equivalent Cs(1) and one Ba(1) atom to form ICs4Ba square pyramids that share corners with four equivalent I(3)Cs4Ba square pyramids, corners with three equivalent I(2)Cs2Ba3 trigonal bipyramids, edges with four equivalent I(3)Cs4Ba square pyramids, and edges with four equivalent I(2)Cs2Ba3 trigonal bipyramids.
CsBaI3 crystallizes in the orthorhombic Pnma space group. 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 (4.15 Å) and one longer (4.30 Å) Cs(1)-I(2) bond length. There are two shorter (4.11 Å) and one longer (4.30 Å) Cs(1)-I(1) bond length. All Cs(1)-I(3) bond lengths are 4.01 Å. Ba(1) is bonded to one I(3), two equivalent I(1), and three equivalent I(2) atoms to form edge-sharing BaI6 octahedra. The Ba(1)-I(3) bond length is 3.36 Å. Both Ba(1)-I(1) bond lengths are 3.46 Å. There are two shorter (3.50 Å) and one longer (3.52 Å) Ba(1)-I(2) bond length. There are three 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 Ba(1) atoms. In the second I site, I(2) is bonded to two equivalent Cs(1) and three equivalent Ba(1) atoms to form distorted ICs2Ba3 trigonal bipyramids that share corners with three equivalent I(3)Cs4Ba square pyramids, corners with four equivalent I(2)Cs2Ba3 trigonal bipyramids, edges with four equivalent I(3)Cs4Ba square pyramids, and edges with two equivalent I(2)Cs2Ba3 trigonal bipyramids. In the third I site, I(3) is bonded to four equivalent Cs(1) and one Ba(1) atom to form ICs4Ba square pyramids that share corners with four equivalent I(3)Cs4Ba square pyramids, corners with three equivalent I(2)Cs2Ba3 trigonal bipyramids, edges with four equivalent I(3)Cs4Ba square pyramids, and edges with four equivalent I(2)Cs2Ba3 trigonal bipyramids.