Ba2P7Cl crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one P(3), two equivalent P(5), four equivalent P(2), and three equivalent Cl(1) atoms. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one P(1), two equivalent P(2), two equivalent P(5), three equivalent P(4), and one Cl(1) atom. There are five inequivalent P sites. In the first P site, P(1) is bonded in a 4-coordinate geometry to one Ba(2), one P(4), and two equivalent P(5) atoms. In the second P site, P(2) is bonded to one Ba(2), two equivalent Ba(1), one P(3), and one P(5) atom to form PBa3P2 trigonal bipyramids that share corners with two equivalent P(4)Ba3P2 square pyramids, corners with two equivalent P(3)BaP3 tetrahedra, corners with two equivalent P(2)Ba3P2 trigonal bipyramids, corners with five equivalent Cl(1)Ba4 trigonal pyramids,  an edgeedge with one P(4)Ba3P2 square pyramid, edges with three equivalent P(2)Ba3P2 trigonal bipyramids, and  an edgeedge with one Cl(1)Ba4 trigonal pyramid. In the third P site, P(3) is bonded to one Ba(1), one P(4), and two equivalent P(2) atoms to form PBaP3 tetrahedra that share corners with four equivalent P(2)Ba3P2 trigonal bipyramids and corners with three equivalent Cl(1)Ba4 trigonal pyramids. In the fourth P site, P(4) is bonded to three equivalent Ba(2), one P(1), and one P(3) atom to form distorted PBa3P2 square pyramids that share corners with two equivalent P(4)Ba3P2 square pyramids, corners with four equivalent P(2)Ba3P2 trigonal bipyramids, corners with three equivalent Cl(1)Ba4 trigonal pyramids, edges with two equivalent P(4)Ba3P2 square pyramids, and edges with two equivalent P(2)Ba3P2 trigonal bipyramids. In the fifth P site, P(5) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one P(1), one P(2), and one P(5) atom. Cl(1) is bonded to one Ba(2) and three equivalent Ba(1) atoms to form distorted ClBa4 trigonal pyramids that share corners with three equivalent P(4)Ba3P2 square pyramids, corners with three equivalent P(3)BaP3 tetrahedra, corners with ten equivalent P(2)Ba3P2 trigonal bipyramids, corners with two equivalent Cl(1)Ba4 trigonal pyramids, edges with two equivalent P(2)Ba3P2 trigonal bipyramids, and edges with two equivalent Cl(1)Ba4 trigonal pyramids.
Ba2P7Cl crystallizes in the monoclinic P2_1/m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one P(3), two equivalent P(5), four equivalent P(2), and three equivalent Cl(1) atoms. The Ba(1)-P(3) bond length is 3.41 Å. Both Ba(1)-P(5) bond lengths are 3.48 Å. There are two shorter (3.39 Å) and two longer (3.42 Å) Ba(1)-P(2) bond lengths. There is one shorter (3.18 Å) and two longer (3.60 Å) Ba(1)-Cl(1) bond lengths. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one P(1), two equivalent P(2), two equivalent P(5), three equivalent P(4), and one Cl(1) atom. The Ba(2)-P(1) bond length is 3.47 Å. Both Ba(2)-P(2) bond lengths are 3.34 Å. Both Ba(2)-P(5) bond lengths are 3.54 Å. There is one shorter (3.44 Å) and two longer (3.59 Å) Ba(2)-P(4) bond lengths. The Ba(2)-Cl(1) bond length is 3.22 Å. There are five inequivalent P sites. In the first P site, P(1) is bonded in a 4-coordinate geometry to one Ba(2), one P(4), and two equivalent P(5) atoms. The P(1)-P(4) bond length is 2.16 Å. Both P(1)-P(5) bond lengths are 2.24 Å. In the second P site, P(2) is bonded to one Ba(2), two equivalent Ba(1), one P(3), and one P(5) atom to form PBa3P2 trigonal bipyramids that share corners with two equivalent P(4)Ba3P2 square pyramids, corners with two equivalent P(3)BaP3 tetrahedra, corners with two equivalent P(2)Ba3P2 trigonal bipyramids, corners with five equivalent Cl(1)Ba4 trigonal pyramids,  an edgeedge with one P(4)Ba3P2 square pyramid, edges with three equivalent P(2)Ba3P2 trigonal bipyramids, and  an edgeedge with one Cl(1)Ba4 trigonal pyramid. The P(2)-P(3) bond length is 2.18 Å. The P(2)-P(5) bond length is 2.15 Å. In the third P site, P(3) is bonded to one Ba(1), one P(4), and two equivalent P(2) atoms to form PBaP3 tetrahedra that share corners with four equivalent P(2)Ba3P2 trigonal bipyramids and corners with three equivalent Cl(1)Ba4 trigonal pyramids. The P(3)-P(4) bond length is 2.19 Å. In the fourth P site, P(4) is bonded to three equivalent Ba(2), one P(1), and one P(3) atom to form distorted PBa3P2 square pyramids that share corners with two equivalent P(4)Ba3P2 square pyramids, corners with four equivalent P(2)Ba3P2 trigonal bipyramids, corners with three equivalent Cl(1)Ba4 trigonal pyramids, edges with two equivalent P(4)Ba3P2 square pyramids, and edges with two equivalent P(2)Ba3P2 trigonal bipyramids. In the fifth P site, P(5) is bonded in a 5-coordinate geometry to one Ba(1), one Ba(2), one P(1), one P(2), and one P(5) atom. The P(5)-P(5) bond length is 2.35 Å. Cl(1) is bonded to one Ba(2) and three equivalent Ba(1) atoms to form distorted ClBa4 trigonal pyramids that share corners with three equivalent P(4)Ba3P2 square pyramids, corners with three equivalent P(3)BaP3 tetrahedra, corners with ten equivalent P(2)Ba3P2 trigonal bipyramids, corners with two equivalent Cl(1)Ba4 trigonal pyramids, edges with two equivalent P(2)Ba3P2 trigonal bipyramids, and edges with two equivalent Cl(1)Ba4 trigonal pyramids.