BaSr2I6 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(3), and four equivalent I(2) atoms. Sr(1) is bonded to two equivalent I(1), two equivalent I(2), and two equivalent I(3) atoms to form a mixture of corner and edge-sharing SrI6 octahedra. The corner-sharing octahedral tilt angles range from 44-61°. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form a mixture of distorted corner and edge-sharing IBa2Sr2 trigonal pyramids. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to one Ba(1) and two equivalent Sr(1) atoms.
BaSr2I6 crystallizes in the monoclinic C2/c space group. Ba(1) is bonded in a 8-coordinate geometry to two equivalent I(1), two equivalent I(3), and four equivalent I(2) atoms. Both Ba(1)-I(1) bond lengths are 3.57 Å. Both Ba(1)-I(3) bond lengths are 3.51 Å. There are two shorter (3.64 Å) and two longer (3.76 Å) Ba(1)-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 a mixture of corner and edge-sharing SrI6 octahedra. The corner-sharing octahedral tilt angles range from 44-61°. Both Sr(1)-I(1) bond lengths are 3.27 Å. There is one shorter (3.36 Å) and one longer (3.38 Å) Sr(1)-I(2) bond length. There is one shorter (3.27 Å) and one longer (3.29 Å) Sr(1)-I(3) bond length. There are three inequivalent I sites. In the first I site, I(1) is bonded in a trigonal planar geometry to one Ba(1) and two equivalent Sr(1) atoms. In the second I site, I(2) is bonded to two equivalent Ba(1) and two equivalent Sr(1) atoms to form a mixture of distorted corner and edge-sharing IBa2Sr2 trigonal pyramids. In the third I site, I(3) is bonded in a trigonal non-coplanar geometry to one Ba(1) and two equivalent Sr(1) atoms.