Ba3YI9 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one I(3), one I(6), two equivalent I(2), and four equivalent I(5) atoms. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one I(4), two equivalent I(1), and two equivalent I(5) atoms. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one I(4), two equivalent I(1), two equivalent I(2), and two equivalent I(5) atoms. Y(1) is bonded in an octahedral geometry to one I(3), one I(6), two equivalent I(1), and two equivalent I(2) atoms. There are six inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Ba(2), one Ba(3), and one Y(1) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(3), and one Y(1) atom. In the third I site, I(3) is bonded in an L-shaped geometry to one Ba(1) and one Y(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Ba(2) and one Ba(3) atom. In the fifth I site, I(5) is bonded to one Ba(2), one Ba(3), and two equivalent Ba(1) atoms to form a mixture of edge and corner-sharing IBa4 tetrahedra. In the sixth I site, I(6) is bonded in a 2-coordinate geometry to one Ba(1) and one Y(1) atom.
Ba3YI9 crystallizes in the orthorhombic Pnma space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one I(3), one I(6), two equivalent I(2), and four equivalent I(5) atoms. The Ba(1)-I(3) bond length is 3.53 Å. The Ba(1)-I(6) bond length is 3.79 Å. Both Ba(1)-I(2) bond lengths are 3.92 Å. There are two shorter (3.60 Å) and two longer (3.68 Å) Ba(1)-I(5) bond lengths. In the second Ba site, Ba(2) is bonded in a 5-coordinate geometry to one I(4), two equivalent I(1), and two equivalent I(5) atoms. The Ba(2)-I(4) bond length is 3.38 Å. Both Ba(2)-I(1) bond lengths are 3.62 Å. Both Ba(2)-I(5) bond lengths are 3.50 Å. In the third Ba site, Ba(3) is bonded in a 7-coordinate geometry to one I(4), two equivalent I(1), two equivalent I(2), and two equivalent I(5) atoms. The Ba(3)-I(4) bond length is 3.48 Å. Both Ba(3)-I(1) bond lengths are 3.60 Å. Both Ba(3)-I(2) bond lengths are 3.51 Å. Both Ba(3)-I(5) bond lengths are 3.92 Å. Y(1) is bonded in an octahedral geometry to one I(3), one I(6), two equivalent I(1), and two equivalent I(2) atoms. The Y(1)-I(3) bond length is 3.00 Å. The Y(1)-I(6) bond length is 3.01 Å. Both Y(1)-I(1) bond lengths are 3.08 Å. Both Y(1)-I(2) bond lengths are 2.97 Å. There are six inequivalent I sites. In the first I site, I(1) is bonded in a trigonal non-coplanar geometry to one Ba(2), one Ba(3), and one Y(1) atom. In the second I site, I(2) is bonded in a 3-coordinate geometry to one Ba(1), one Ba(3), and one Y(1) atom. In the third I site, I(3) is bonded in an L-shaped geometry to one Ba(1) and one Y(1) atom. In the fourth I site, I(4) is bonded in a bent 120 degrees geometry to one Ba(2) and one Ba(3) atom. In the fifth I site, I(5) is bonded to one Ba(2), one Ba(3), and two equivalent Ba(1) atoms to form a mixture of edge and corner-sharing IBa4 tetrahedra. In the sixth I site, I(6) is bonded in a 2-coordinate geometry to one Ba(1) and one Y(1) atom.