BaC4H8O7 crystallizes in the monoclinic P2_1/c space group. Ba(1) is bonded in a 10-coordinate geometry to one H(3), one O(1), one O(2), one O(3), one O(6), one O(7), two equivalent O(4), and two equivalent O(5) atoms. The Ba(1)-H(3) bond length is 3.14 Å. The Ba(1)-O(1) bond length is 2.81 Å. The Ba(1)-O(2) bond length is 2.80 Å. The Ba(1)-O(3) bond length is 3.00 Å. The Ba(1)-O(6) bond length is 3.16 Å. The Ba(1)-O(7) bond length is 2.80 Å. There is one shorter (2.67 Å) and one longer (2.86 Å) Ba(1)-O(4) bond length. There is one shorter (2.89 Å) and one longer (3.29 Å) Ba(1)-O(5) bond length. There are four 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(6) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(6) bond length is 1.28 Å. In the second C site, C(2) is bonded in a distorted water-like geometry to one H(1) and one O(2) atom. The C(2)-H(1) bond length is 1.10 Å. The C(2)-O(2) bond length is 1.43 Å. In the third C site, C(3) is bonded in a distorted water-like geometry to one H(2) and one H(3) atom. The C(3)-H(2) bond length is 1.09 Å. The C(3)-H(3) bond length is 1.10 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one O(4) and one O(7) atom. The C(4)-O(4) bond length is 1.28 Å. The C(4)-O(7) bond length is 1.27 Å. There are eight 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 single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one Ba(1) and one C(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(5) atom. The H(4)-O(5) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(3) atom. The H(5)-O(3) bond length is 0.98 Å. In the sixth H site, H(6) is bonded in a distorted linear geometry to one O(3) and one O(6) atom. The H(6)-O(3) bond length is 1.02 Å. The H(6)-O(6) bond length is 1.58 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(5) atom. The H(7)-O(5) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(2) atom. The H(8)-O(2) bond length is 1.00 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one Ba(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Ba(1), one C(2), and one H(8) atom. In the third O site, O(3) is bonded in a water-like geometry to one Ba(1), one H(5), and one H(6) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(4) atom. In the fifth O site, O(5) is bonded in a water-like geometry to two equivalent Ba(1), one H(4), and one H(7) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ba(1), one C(1), and one H(6) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one Ba(1) and one C(4) atom. Linkers: 2 [O]C(=O)C[C@@H](O)C([O])=O ,2 [O]C(=O)C[C@H](O)C([O])=O. Metal clusters: 4 [Ba]. The MOF has largest included sphere 2.16 A, density 2.51 g/cm3, surface area 2778.89 m2/g, accessible volume 0.07 cm3/g