Ba2SrI6 is Hydrophilite-derived structured and crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent I(3) and four equivalent I(1) atoms to form BaI6 octahedra that share corners with two equivalent Ba(2)I6 octahedra, corners with six equivalent Sr(1)I6 octahedra, and edges with two equivalent Ba(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. In the second Ba site, Ba(2) is bonded to two equivalent I(3) and four equivalent I(2) atoms to form BaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Sr(1)I6 octahedra, corners with four equivalent Ba(2)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form SrI6 octahedra that share corners with two equivalent Ba(2)I6 octahedra, corners with six equivalent Ba(1)I6 octahedra, and edges with two equivalent Ba(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Sr(1) atom. In the second I site, I(2) is bonded in a trigonal planar geometry to two equivalent Ba(2) and one Sr(1) atom. In the third I site, I(3) is bonded in a trigonal planar geometry to one Ba(1), one Ba(2), and one Sr(1) atom.
Ba2SrI6 is Hydrophilite-derived structured and crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded to two equivalent I(3) and four equivalent I(1) atoms to form BaI6 octahedra that share corners with two equivalent Ba(2)I6 octahedra, corners with six equivalent Sr(1)I6 octahedra, and edges with two equivalent Ba(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-55°. Both Ba(1)-I(3) bond lengths are 3.47 Å. All Ba(1)-I(1) bond lengths are 3.48 Å. In the second Ba site, Ba(2) is bonded to two equivalent I(3) and four equivalent I(2) atoms to form BaI6 octahedra that share corners with two equivalent Ba(1)I6 octahedra, corners with two equivalent Sr(1)I6 octahedra, corners with four equivalent Ba(2)I6 octahedra, and edges with two equivalent Sr(1)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. Both Ba(2)-I(3) bond lengths are 3.49 Å. There are two shorter (3.47 Å) and two longer (3.48 Å) Ba(2)-I(2) bond lengths. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form SrI6 octahedra that share corners with two equivalent Ba(2)I6 octahedra, corners with six equivalent Ba(1)I6 octahedra, and edges with two equivalent Ba(2)I6 octahedra. The corner-sharing octahedral tilt angles range from 50-51°. Both Sr(1)-I(1) bond lengths are 3.32 Å. Both Sr(1)-I(2) bond lengths are 3.33 Å. Both Sr(1)-I(3) bond lengths are 3.30 Å. There are three inequivalent I sites. In the first I site, I(1) is bonded in a distorted trigonal planar geometry to two equivalent Ba(1) and one Sr(1) atom. In the second I site, I(2) is bonded in a trigonal planar geometry to two equivalent Ba(2) and one Sr(1) atom. In the third I site, I(3) is bonded in a trigonal planar geometry to one Ba(1), one Ba(2), and one Sr(1) atom.