Ba4Fe2I5S4 crystallizes in the tetragonal I4/m space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent S(1), one I(2), and five equivalent I(1) atoms. Fe(1) is bonded to four equivalent S(1) atoms to form edge-sharing FeS4 tetrahedra. S(1) is bonded in a 5-coordinate geometry to three equivalent Ba(1) and two equivalent Fe(1) atoms. There are two inequivalent I sites. In the first I site, I(1) is bonded to five equivalent Ba(1) atoms to form a mixture of distorted edge and corner-sharing IBa5 trigonal bipyramids. In the second I site, I(2) is bonded in a square co-planar geometry to four equivalent Ba(1) atoms.
Ba4Fe2I5S4 crystallizes in the tetragonal I4/m space group. Ba(1) is bonded in a 9-coordinate geometry to three equivalent S(1), one I(2), and five equivalent I(1) atoms. There is one shorter (3.22 Å) and two longer (3.34 Å) Ba(1)-S(1) bond lengths. The Ba(1)-I(2) bond length is 3.61 Å. There are a spread of Ba(1)-I(1) bond distances ranging from 3.67-3.78 Å. Fe(1) is bonded to four equivalent S(1) atoms to form edge-sharing FeS4 tetrahedra. All Fe(1)-S(1) bond lengths are 2.25 Å. S(1) is bonded in a 5-coordinate geometry to three equivalent Ba(1) and two equivalent Fe(1) atoms. There are two inequivalent I sites. In the first I site, I(1) is bonded to five equivalent Ba(1) atoms to form a mixture of distorted edge and corner-sharing IBa5 trigonal bipyramids. In the second I site, I(2) is bonded in a square co-planar geometry to four equivalent Ba(1) atoms.