BaCaI4 crystallizes in the orthorhombic Pbcm space group. Ba(1) is bonded to one I(2), two equivalent I(1), and four equivalent I(3) atoms to form distorted BaI7 hexagonal pyramids that share corners with two equivalent Ba(1)I7 hexagonal pyramids, corners with six equivalent Ca(1)I6 octahedra, edges with two equivalent Ba(1)I7 hexagonal pyramids, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 36-68°. Ca(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ba(1)I7 hexagonal pyramids, corners with four equivalent Ca(1)I6 octahedra, and edges with two equivalent Ba(1)I7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 45-57°. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(1) and two equivalent Ca(1) atoms to form distorted corner-sharing IBa2Ca2 tetrahedra. In the second I site, I(2) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Ca(1) atom.
BaCaI4 crystallizes in the orthorhombic Pbcm space group. Ba(1) is bonded to one I(2), two equivalent I(1), and four equivalent I(3) atoms to form distorted BaI7 hexagonal pyramids that share corners with two equivalent Ba(1)I7 hexagonal pyramids, corners with six equivalent Ca(1)I6 octahedra, edges with two equivalent Ba(1)I7 hexagonal pyramids, and edges with two equivalent Ca(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 36-68°. The Ba(1)-I(2) bond length is 3.48 Å. Both Ba(1)-I(1) bond lengths are 3.76 Å. There are two shorter (3.61 Å) and two longer (3.69 Å) Ba(1)-I(3) bond lengths. Ca(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form CaI6 octahedra that share corners with six equivalent Ba(1)I7 hexagonal pyramids, corners with four equivalent Ca(1)I6 octahedra, and edges with two equivalent Ba(1)I7 hexagonal pyramids. The corner-sharing octahedral tilt angles range from 45-57°. Both Ca(1)-I(1) bond lengths are 3.18 Å. Both Ca(1)-I(2) bond lengths are 3.16 Å. Both Ca(1)-I(3) bond lengths are 3.07 Å. There are three inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(1) and two equivalent Ca(1) atoms to form distorted corner-sharing IBa2Ca2 tetrahedra. In the second I site, I(2) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Ca(1) atoms. In the third I site, I(3) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Ca(1) atom.