BaC8N3H9O5 crystallizes in the monoclinic Cc space group. Ba(1) is bonded in a 9-coordinate geometry to one N(1), one O(1), one O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms. The Ba(1)-N(1) bond length is 2.92 Å. The Ba(1)-O(1) bond length is 2.73 Å. The Ba(1)-O(2) bond length is 2.68 Å. There is one shorter (2.70 Å) and one longer (2.93 Å) Ba(1)-O(3) bond length. There is one shorter (2.71 Å) and one longer (3.07 Å) Ba(1)-O(4) bond length. There is one shorter (2.90 Å) and one longer (2.93 Å) Ba(1)-O(5) bond length. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.27 Å. The C(1)-O(2) bond length is 1.28 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(4), and one N(1) atom. The C(2)-C(4) bond length is 1.41 Å. The C(2)-N(1) bond length is 1.38 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(2) atom. The C(3)-N(1) bond length is 1.33 Å. The C(3)-N(2) bond length is 1.35 Å. The C(3)-H(2) bond length is 1.08 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(2), one C(5), and one N(2) atom. The C(4)-C(5) bond length is 1.49 Å. The C(4)-N(2) bond length is 1.38 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.27 Å. The C(5)-O(4) bond length is 1.27 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(3), one H(3), and one O(5) atom. The C(6)-N(3) bond length is 1.34 Å. The C(6)-H(3) bond length is 1.11 Å. The C(6)-O(5) bond length is 1.25 Å. In the seventh C site, C(7) is bonded to one N(3), one H(4), one H(5), and one H(6) atom to form corner-sharing CH3N tetrahedra. The C(7)-N(3) bond length is 1.46 Å. The C(7)-H(4) bond length is 1.09 Å. The C(7)-H(5) bond length is 1.10 Å. The C(7)-H(6) bond length is 1.10 Å. In the eighth C site, C(8) is bonded to one N(3), one H(7), one H(8), and one H(9) atom to form corner-sharing CH3N tetrahedra. The C(8)-N(3) bond length is 1.46 Å. The C(8)-H(7) bond length is 1.10 Å. The C(8)-H(8) bond length is 1.10 Å. The C(8)-H(9) bond length is 1.10 Å. There are three inequivalent N sites. In the first N site, N(1) is bonded in a distorted water-like geometry to one Ba(1), one C(2), and one C(3) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one C(3), one C(4), and one H(1) atom. The N(2)-H(1) bond length is 1.05 Å. In the third N site, N(3) is bonded in a trigonal planar geometry to one C(6), one C(7), and one C(8) atom. There are nine inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(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 C(6) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(7) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(7) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(7) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(8) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(8) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(8) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(5) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(5) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(6) atom. Linkers: 2 [O]C(=O)c1nc[nH]c1C([O])=O. Metal clusters: 2 [Ba]. The MOF has largest included sphere 2.03 A, density 2.19 g/cm3, surface area 3152.85 m2/g, accessible volume 0.08 cm3/g