Ba3P3I2 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 P(2), two equivalent P(1), two equivalent P(3), and three equivalent I(2) atoms. In the second Ba site, Ba(2) is bonded to one P(3), two equivalent P(1), two equivalent P(2), one I(2), and two equivalent I(1) atoms to form distorted BaP5I3 hexagonal bipyramids that share corners with two equivalent P(2)Ba5P octahedra, corners with two equivalent P(3)Ba5P octahedra, and faces with two equivalent Ba(2)P5I3 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-112°. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent P(1), two equivalent P(2), two equivalent P(3), one I(2), and three equivalent I(1) atoms. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), two equivalent Ba(3), one P(2), and one P(3) atom. In the second P site, P(2) is bonded to one Ba(1), two equivalent Ba(2), two equivalent Ba(3), and one P(1) atom to form distorted PBa5P octahedra that share corners with two equivalent Ba(2)P5I3 hexagonal bipyramids, corners with two equivalent P(3)Ba5P octahedra, corners with three equivalent I(2)Ba5 trigonal bipyramids, corners with six equivalent I(1)Ba5 trigonal bipyramids, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent P(3)Ba5P octahedra, edges with two equivalent I(1)Ba5 trigonal bipyramids, edges with two equivalent I(2)Ba5 trigonal bipyramids, and  a faceface with one P(3)Ba5P octahedra. The corner-sharing octahedral tilt angles are 57°. In the third P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one P(1) atom to form distorted PBa5P octahedra that share corners with two equivalent Ba(2)P5I3 hexagonal bipyramids, corners with two equivalent P(2)Ba5P octahedra, corners with two equivalent I(1)Ba5 trigonal bipyramids, corners with seven equivalent I(2)Ba5 trigonal bipyramids, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent P(3)Ba5P octahedra,  an edgeedge with one I(2)Ba5 trigonal bipyramid, edges with three equivalent I(1)Ba5 trigonal bipyramids, and  a faceface with one P(2)Ba5P octahedra. The corner-sharing octahedral tilt angles are 57°. There are two inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(2) and three equivalent Ba(3) atoms to form distorted IBa5 trigonal bipyramids that share corners with two equivalent P(3)Ba5P octahedra, corners with six equivalent P(2)Ba5P octahedra,  a cornercorner with one I(2)Ba5 trigonal bipyramid, edges with two equivalent P(2)Ba5P octahedra, edges with three equivalent P(3)Ba5P octahedra, edges with two equivalent I(2)Ba5 trigonal bipyramids, and edges with four equivalent I(1)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-45°. In the second I site, I(2) is bonded to one Ba(2), one Ba(3), and three equivalent Ba(1) atoms to form distorted IBa5 trigonal bipyramids that share corners with three equivalent P(2)Ba5P octahedra, corners with seven equivalent P(3)Ba5P octahedra,  a cornercorner with one I(1)Ba5 trigonal bipyramid, corners with two equivalent I(2)Ba5 trigonal bipyramids,  an edgeedge with one P(3)Ba5P octahedra, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent I(1)Ba5 trigonal bipyramids, and edges with two equivalent I(2)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-67°.
Ba3P3I2 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 P(2), two equivalent P(1), two equivalent P(3), and three equivalent I(2) atoms. The Ba(1)-P(2) bond length is 3.25 Å. Both Ba(1)-P(1) bond lengths are 3.54 Å. Both Ba(1)-P(3) bond lengths are 3.29 Å. There are two shorter (3.56 Å) and one longer (3.68 Å) Ba(1)-I(2) bond length. In the second Ba site, Ba(2) is bonded to one P(3), two equivalent P(1), two equivalent P(2), one I(2), and two equivalent I(1) atoms to form distorted BaP5I3 hexagonal bipyramids that share corners with two equivalent P(2)Ba5P octahedra, corners with two equivalent P(3)Ba5P octahedra, and faces with two equivalent Ba(2)P5I3 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 43-112°. The Ba(2)-P(3) bond length is 3.19 Å. Both Ba(2)-P(1) bond lengths are 3.41 Å. Both Ba(2)-P(2) bond lengths are 3.28 Å. The Ba(2)-I(2) bond length is 3.67 Å. Both Ba(2)-I(1) bond lengths are 3.51 Å. In the third Ba site, Ba(3) is bonded in a 10-coordinate geometry to two equivalent P(1), two equivalent P(2), two equivalent P(3), one I(2), and three equivalent I(1) atoms. Both Ba(3)-P(1) bond lengths are 3.57 Å. Both Ba(3)-P(2) bond lengths are 3.29 Å. Both Ba(3)-P(3) bond lengths are 3.33 Å. The Ba(3)-I(2) bond length is 4.13 Å. There are two shorter (3.60 Å) and one longer (3.72 Å) Ba(3)-I(1) bond length. There are three inequivalent P sites. In the first P site, P(1) is bonded in a 8-coordinate geometry to two equivalent Ba(1), two equivalent Ba(2), two equivalent Ba(3), one P(2), and one P(3) atom. The P(1)-P(2) bond length is 2.15 Å. The P(1)-P(3) bond length is 2.13 Å. In the second P site, P(2) is bonded to one Ba(1), two equivalent Ba(2), two equivalent Ba(3), and one P(1) atom to form distorted PBa5P octahedra that share corners with two equivalent Ba(2)P5I3 hexagonal bipyramids, corners with two equivalent P(3)Ba5P octahedra, corners with three equivalent I(2)Ba5 trigonal bipyramids, corners with six equivalent I(1)Ba5 trigonal bipyramids, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent P(3)Ba5P octahedra, edges with two equivalent I(1)Ba5 trigonal bipyramids, edges with two equivalent I(2)Ba5 trigonal bipyramids, and  a faceface with one P(3)Ba5P octahedra. The corner-sharing octahedral tilt angles are 57°. In the third P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), and one P(1) atom to form distorted PBa5P octahedra that share corners with two equivalent Ba(2)P5I3 hexagonal bipyramids, corners with two equivalent P(2)Ba5P octahedra, corners with two equivalent I(1)Ba5 trigonal bipyramids, corners with seven equivalent I(2)Ba5 trigonal bipyramids, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent P(3)Ba5P octahedra,  an edgeedge with one I(2)Ba5 trigonal bipyramid, edges with three equivalent I(1)Ba5 trigonal bipyramids, and  a faceface with one P(2)Ba5P octahedra. The corner-sharing octahedral tilt angles are 57°. There are two inequivalent I sites. In the first I site, I(1) is bonded to two equivalent Ba(2) and three equivalent Ba(3) atoms to form distorted IBa5 trigonal bipyramids that share corners with two equivalent P(3)Ba5P octahedra, corners with six equivalent P(2)Ba5P octahedra,  a cornercorner with one I(2)Ba5 trigonal bipyramid, edges with two equivalent P(2)Ba5P octahedra, edges with three equivalent P(3)Ba5P octahedra, edges with two equivalent I(2)Ba5 trigonal bipyramids, and edges with four equivalent I(1)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-45°. In the second I site, I(2) is bonded to one Ba(2), one Ba(3), and three equivalent Ba(1) atoms to form distorted IBa5 trigonal bipyramids that share corners with three equivalent P(2)Ba5P octahedra, corners with seven equivalent P(3)Ba5P octahedra,  a cornercorner with one I(1)Ba5 trigonal bipyramid, corners with two equivalent I(2)Ba5 trigonal bipyramids,  an edgeedge with one P(3)Ba5P octahedra, edges with two equivalent P(2)Ba5P octahedra, edges with two equivalent I(1)Ba5 trigonal bipyramids, and edges with two equivalent I(2)Ba5 trigonal bipyramids. The corner-sharing octahedral tilt angles range from 13-67°.