Ba5P9 crystallizes in the orthorhombic Fdd2 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to two equivalent P(1), two equivalent P(3), two equivalent P(5), and three equivalent P(2) atoms. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent P(1), two equivalent P(2), two equivalent P(3), and four equivalent P(5) atoms. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to one P(2), one P(4), one P(5), two equivalent P(1), and three equivalent P(3) atoms. There are five inequivalent P sites. In the first P site, P(1) is bonded in a 7-coordinate geometry to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), one P(3), and one P(5) atom. In the second P site, P(2) is bonded in a 7-coordinate geometry to one Ba(2), one Ba(3), three equivalent Ba(1), one P(4), and one P(5) atom. In the third P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), three equivalent Ba(3), and one P(1) atom to form a mixture of distorted face and corner-sharing PBa6P pentagonal bipyramids. In the fourth P site, P(4) is bonded in a 4-coordinate geometry to two equivalent Ba(3) and two equivalent P(2) atoms. In the fifth P site, P(5) is bonded in a 7-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one P(1), and one P(2) atom.
Ba5P9 crystallizes in the orthorhombic Fdd2 space group. There are three inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 7-coordinate geometry to two equivalent P(1), two equivalent P(3), two equivalent P(5), and three equivalent P(2) atoms. There is one shorter (3.28 Å) and one longer (3.45 Å) Ba(1)-P(1) bond length. There is one shorter (3.33 Å) and one longer (3.40 Å) Ba(1)-P(3) bond length. There is one shorter (3.29 Å) and one longer (3.36 Å) Ba(1)-P(5) bond length. There are a spread of Ba(1)-P(2) bond distances ranging from 3.38-3.91 Å. In the second Ba site, Ba(2) is bonded in a 10-coordinate geometry to two equivalent P(1), two equivalent P(2), two equivalent P(3), and four equivalent P(5) atoms. Both Ba(2)-P(1) bond lengths are 3.58 Å. Both Ba(2)-P(2) bond lengths are 3.38 Å. Both Ba(2)-P(3) bond lengths are 3.40 Å. There are two shorter (3.42 Å) and two longer (3.77 Å) Ba(2)-P(5) bond lengths. In the third Ba site, Ba(3) is bonded in a 8-coordinate geometry to one P(2), one P(4), one P(5), two equivalent P(1), and three equivalent P(3) atoms. The Ba(3)-P(2) bond length is 3.46 Å. The Ba(3)-P(4) bond length is 3.36 Å. The Ba(3)-P(5) bond length is 3.68 Å. There is one shorter (3.18 Å) and one longer (3.23 Å) Ba(3)-P(1) bond length. There are a spread of Ba(3)-P(3) bond distances ranging from 3.17-3.42 Å. There are five inequivalent P sites. In the first P site, P(1) is bonded in a 7-coordinate geometry to one Ba(2), two equivalent Ba(1), two equivalent Ba(3), one P(3), and one P(5) atom. The P(1)-P(3) bond length is 2.16 Å. The P(1)-P(5) bond length is 2.19 Å. In the second P site, P(2) is bonded in a 7-coordinate geometry to one Ba(2), one Ba(3), three equivalent Ba(1), one P(4), and one P(5) atom. The P(2)-P(4) bond length is 2.20 Å. The P(2)-P(5) bond length is 2.19 Å. In the third P site, P(3) is bonded to one Ba(2), two equivalent Ba(1), three equivalent Ba(3), and one P(1) atom to form a mixture of distorted face and corner-sharing PBa6P pentagonal bipyramids. In the fourth P site, P(4) is bonded in a 4-coordinate geometry to two equivalent Ba(3) and two equivalent P(2) atoms. In the fifth P site, P(5) is bonded in a 7-coordinate geometry to one Ba(3), two equivalent Ba(1), two equivalent Ba(2), one P(1), and one P(2) atom.