BaC7NH4O5 crystallizes in the monoclinic C2/c space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 8-coordinate geometry to one N(1), one N(2), one O(1), one O(4), one O(5), one O(6), and two equivalent O(8) atoms. The Ba(1)-N(1) bond length is 3.01 Å. The Ba(1)-N(2) bond length is 2.94 Å. The Ba(1)-O(1) bond length is 2.79 Å. The Ba(1)-O(4) bond length is 2.82 Å. The Ba(1)-O(5) bond length is 2.73 Å. The Ba(1)-O(6) bond length is 2.76 Å. There is one shorter (2.75 Å) and one longer (2.79 Å) Ba(1)-O(8) bond length. In the second Ba site, Ba(2) is bonded in a 9-coordinate geometry to one O(10), one O(3), one O(4), one O(6), one O(9), two equivalent O(1), and two equivalent O(2) atoms. The Ba(2)-O(10) bond length is 2.76 Å. The Ba(2)-O(3) bond length is 2.80 Å. The Ba(2)-O(4) bond length is 2.90 Å. The Ba(2)-O(6) bond length is 2.83 Å. The Ba(2)-O(9) bond length is 2.77 Å. There is one shorter (2.97 Å) and one longer (3.01 Å) Ba(2)-O(1) bond length. There is one shorter (2.78 Å) and one longer (2.87 Å) Ba(2)-O(2) bond length. There are fourteen inequivalent C sites. In the first C site, C(13) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(5), and one O(6) atom. The C(13)-C(3) bond length is 1.51 Å. The C(13)-O(5) bond length is 1.27 Å. The C(13)-O(6) bond length is 1.27 Å. In the second C site, C(14) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(7), and one O(8) atom. The C(14)-C(1) bond length is 1.52 Å. The C(14)-O(7) bond length is 1.26 Å. The C(14)-O(8) bond length is 1.28 Å. In the third C site, C(1) is bonded in a distorted trigonal planar geometry to one C(14), one C(2), and one N(1) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-N(1) bond length is 1.34 Å. In the fourth C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(1) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-H(1) bond length is 1.09 Å. In the fifth C site, C(3) is bonded in a trigonal planar geometry to one C(13), one C(2), and one C(4) atom. The C(3)-C(4) bond length is 1.39 Å. In the sixth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(2) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-H(2) bond length is 1.09 Å. In the seventh C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one C(6), and one N(1) atom. The C(5)-C(6) bond length is 1.49 Å. The C(5)-N(1) bond length is 1.35 Å. In the eighth C site, C(6) is bonded in a distorted trigonal planar geometry to one C(5), one C(7), and one N(2) atom. The C(6)-C(7) bond length is 1.40 Å. The C(6)-N(2) bond length is 1.35 Å. In the ninth C site, C(7) is bonded in a distorted single-bond geometry to one C(6), one C(8), and one H(3) atom. The C(7)-C(8) bond length is 1.39 Å. The C(7)-H(3) bond length is 1.09 Å. In the tenth C site, C(8) is bonded in a trigonal planar geometry to one C(12), one C(7), and one C(9) atom. The C(8)-C(12) bond length is 1.51 Å. The C(8)-C(9) bond length is 1.40 Å. In the eleventh C site, C(9) is bonded in a distorted single-bond geometry to one C(10), one C(8), and one H(4) atom. The C(9)-C(10) bond length is 1.40 Å. The C(9)-H(4) bond length is 1.09 Å. In the twelfth C site, C(10) is bonded in a distorted trigonal planar geometry to one C(11), one C(9), and one N(2) atom. The C(10)-C(11) bond length is 1.51 Å. The C(10)-N(2) bond length is 1.34 Å. In the thirteenth C site, C(11) is bonded in a distorted bent 120 degrees geometry to one C(10), one O(1), and one O(2) atom. The C(11)-O(1) bond length is 1.28 Å. The C(11)-O(2) bond length is 1.27 Å. In the fourteenth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(3), and one O(4) atom. The C(12)-O(3) bond length is 1.27 Å. The C(12)-O(4) bond length is 1.27 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a bent 120 degrees geometry to one Ba(1), one C(1), and one C(5) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one Ba(1), one C(10), and one C(6) atom. 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(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(9) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(9) atom. The H(5)-O(9) bond length is 1.00 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(9) atom. The H(6)-O(9) bond length is 0.97 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(10) atom. The H(7)-O(10) bond length is 0.99 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(10) atom. The H(8)-O(10) bond length is 0.99 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(1), two equivalent Ba(2), and one C(11) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Ba(2) and one C(11) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Ba(2) and one C(12) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(12) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one Ba(1) and one C(13) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Ba(1), one Ba(2), and one C(13) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one C(14) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to two equivalent Ba(1) and one C(14) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Ba(2), one H(5), and one H(6) atom. In the tenth O site, O(10) is bonded in a water-like geometry to one Ba(2), one H(7), and one H(8) atom. Linkers: 4 [O]C(=O)c1cc(C([O])=O)nc(-c2cc(C([O])=O)cc(C([O])=O)n2)c1. Metal clusters: 8 [Ba]. The MOF has largest included sphere 1.91 A, density 2.64 g/cm3, surface area 2305.45 m2/g, accessible volume 0.03 cm3/g