BaPH7(CO4)2 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. The Ba(1)-O(1) bond length is 2.77 Å. The Ba(1)-O(3) bond length is 2.91 Å. The Ba(1)-O(4) bond length is 2.72 Å. The Ba(1)-O(5) bond length is 2.83 Å. The Ba(1)-O(6) bond length is 2.77 Å. The Ba(1)-O(7) bond length is 2.81 Å. The Ba(1)-O(8) bond length is 2.84 Å. There is one shorter (2.88 Å) and one longer (2.90 Å) Ba(1)-O(2) bond length. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(2) atom. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.26 Å. In the second C site, C(2) is bonded in a 2-coordinate geometry to one P(1), one H(1), and one O(3) atom. The C(2)-P(1) bond length is 1.87 Å. The C(2)-H(1) bond length is 1.10 Å. The C(2)-O(3) bond length is 1.43 Å. P(1) is bonded in a distorted tetrahedral geometry to one C(2), one O(4), one O(5), and one O(6) atom. The P(1)-O(4) bond length is 1.53 Å. The P(1)-O(5) bond length is 1.59 Å. The P(1)-O(6) bond length is 1.51 Å. There are seven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(2) atom. In the second H site, H(2) is bonded in a linear geometry to one O(3) and one O(7) atom. The H(2)-O(3) bond length is 1.03 Å. The H(2)-O(7) bond length is 1.55 Å. In the third H site, H(3) is bonded in a linear geometry to one O(1) and one O(5) atom. The H(3)-O(1) bond length is 1.44 Å. The H(3)-O(5) bond length is 1.06 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(7) atom. The H(4)-O(7) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(8) atom. The H(5)-O(8) bond length is 1.00 Å. In the sixth H site, H(6) is bonded in a distorted linear geometry to one O(4) and one O(7) atom. The H(6)-O(4) bond length is 1.61 Å. The H(6)-O(7) bond length is 1.01 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(8) atom. The H(7)-O(8) bond length is 1.00 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one C(1), and one H(3) atom. In the second O site, O(2) is bonded in a single-bond geometry to two equivalent Ba(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Ba(1), one C(2), and one H(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to one Ba(1), one P(1), and one H(6) atom. In the fifth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one P(1), and one H(3) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(1) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal non-coplanar geometry to one Ba(1), one H(2), one H(4), and one H(6) atom. In the eighth O site, O(8) is bonded in a water-like geometry to one Ba(1), one H(5), and one H(7) atom. Linkers: 2 [O]C(=O)[C@H](O)P([O])(=O)O ,2 [O]C(=O)[C@@H](O)P([O])(=O)O. Metal clusters: 4 [Ba]. The MOF has largest included sphere 2.00 A, density 2.73 g/cm3, surface area 2378.81 m2/g, accessible volume 0.05 cm3/g