Ni2C14N2H8O9 crystallizes in the monoclinic C2/c space group. Ni(1) is bonded to one N(1), one O(1), one O(3), one O(4), and one O(5) atom to form corner-sharing NiNO4 square pyramids. The Ni(1)-N(1) bond length is 2.10 Å. The Ni(1)-O(1) bond length is 2.05 Å. The Ni(1)-O(3) bond length is 2.02 Å. The Ni(1)-O(4) bond length is 2.04 Å. The Ni(1)-O(5) bond length is 2.13 Å. There are seven inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(4), one C(5), and one C(7) atom. The C(1)-C(4) bond length is 1.39 Å. The C(1)-C(5) bond length is 1.51 Å. The C(1)-C(7) bond length is 1.39 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(7) and one H(3) atom. The C(2)-C(7) bond length is 1.39 Å. The C(2)-H(3) bond length is 0.93 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(1), and one O(2) atom. The C(3)-C(7) bond length is 1.51 Å. The C(3)-O(1) bond length is 1.26 Å. The C(3)-O(2) bond length is 1.25 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(1), one N(1), and one H(1) atom. The C(4)-N(1) bond length is 1.34 Å. The C(4)-H(1) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(1), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.26 Å. The C(5)-O(4) bond length is 1.25 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one N(1) and one H(2) atom. The C(6)-N(1) bond length is 1.34 Å. The C(6)-H(2) bond length is 0.93 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(1), one C(2), and one C(3) atom. N(1) is bonded in a trigonal planar geometry to one Ni(1), one C(4), and one C(6) atom. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(4) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(6) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(2) 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 0.83 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(3) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(3) atom. In the third O site, O(5) is bonded in a water-like geometry to two equivalent Ni(1) and two equivalent H(4) atoms. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ni(1) and one C(5) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one Ni(1) and one C(5) atom. Linkers: 4 [O]C(=O)c1ccncc1C([O])=O. Metal clusters: 2 O.O=[C]O[Ni]1O[C]O[Ni](O[C]=O)O[C]O1. The MOF has largest included sphere 4.75 A, density 1.46 g/cm3, surface area 3280.09 m2/g, accessible volume 0.25 cm3/g