BaC3H3O7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(6), one O(7), two equivalent O(3), and two equivalent O(5) atoms. The Ba(1)-O(1) bond length is 2.78 Å. The Ba(1)-O(2) bond length is 3.15 Å. The Ba(1)-O(4) bond length is 2.85 Å. The Ba(1)-O(6) bond length is 2.87 Å. The Ba(1)-O(7) bond length is 2.73 Å. There is one shorter (2.77 Å) and one longer (2.84 Å) Ba(1)-O(3) bond length. There is one shorter (2.76 Å) and one longer (2.87 Å) Ba(1)-O(5) bond length. There are three 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(4) atom. The C(1)-O(1) bond length is 1.25 Å. The C(1)-O(4) bond length is 1.27 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(6) atom. The C(2)-O(2) bond length is 1.32 Å. The C(2)-O(6) bond length is 1.23 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(7) atom. The C(3)-O(5) bond length is 1.27 Å. The C(3)-O(7) bond length is 1.27 Å. There are three inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(2) and one O(4) atom. The H(1)-O(2) bond length is 1.06 Å. The H(1)-O(4) bond length is 1.47 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(3) atom. The H(2)-O(3) bond length is 0.99 Å. In the third H site, H(3) is bonded in a distorted single-bond geometry to one O(3) and one O(7) atom. The H(3)-O(3) bond length is 1.01 Å. The H(3)-O(7) bond length is 1.65 Å. There are seven inequivalent O sites. In the first O site, O(2) is bonded in a bent 120 degrees geometry to one Ba(1), one C(2), and one H(1) atom. In the second O site, O(3) is bonded in a water-like geometry to two equivalent Ba(1), one H(2), and one H(3) atom. In the third O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one C(1), and one H(1) atom. In the fourth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(3) atom. In the fifth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(1) and one C(2) atom. In the sixth O site, O(7) is bonded in a distorted trigonal planar geometry to one Ba(1), one C(3), and one H(3) atom. In the seventh O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one C(1) atom. Linkers: 4 [O]C(=O)C(=O)O ,1 [O]C(=O)C([O])=O. Metal clusters: 4 [Ba]. The MOF has largest included sphere 1.74 A, density 2.79 g/cm3, surface area 2489.75 m2/g, accessible volume 0.05 cm3/g