NiC5N2H8O7 crystallizes in the orthorhombic P2_12_12_1 space group. Ni(1) is bonded in an octahedral geometry to one N(1), one O(1), one O(2), one O(3), one O(5), and one O(6) atom. The Ni(1)-N(1) bond length is 2.04 Å. The Ni(1)-O(1) bond length is 2.05 Å. The Ni(1)-O(2) bond length is 2.07 Å. The Ni(1)-O(3) bond length is 2.06 Å. The Ni(1)-O(5) bond length is 2.10 Å. The Ni(1)-O(6) bond length is 2.08 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one N(2), and one O(4) atom. The C(1)-N(1) bond length is 1.35 Å. The C(1)-N(2) bond length is 1.38 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 C(3), one N(2), and one O(5) atom. The C(2)-C(3) bond length is 1.42 Å. The C(2)-N(2) bond length is 1.37 Å. The C(2)-O(5) bond length is 1.27 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(2), one C(4), and one H(8) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-H(8) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3) and one N(1) atom. The C(4)-N(1) bond length is 1.36 Å. In the fifth C site, C(5) is bonded in a bent 120 degrees geometry to one O(6) and one O(7) atom. The C(5)-O(6) bond length is 1.29 Å. The C(5)-O(7) bond length is 1.26 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one Ni(1), one C(1), and one C(4) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one C(1), one C(2), and one H(7) atom. The N(2)-H(7) bond length is 1.03 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.99 Å. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(1) and one O(4) atom. The H(2)-O(1) bond length is 1.00 Å. The H(2)-O(4) bond length is 1.67 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(2) atom. The H(3)-O(2) bond length is 0.98 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(2) and one O(5) atom. The H(4)-O(2) bond length is 1.00 Å. The H(4)-O(5) bond length is 1.74 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 0.99 Å. In the sixth H site, H(6) is bonded in a distorted single-bond geometry to one O(3) and one O(4) atom. The H(6)-O(3) bond length is 1.01 Å. The H(6)-O(4) bond length is 1.64 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one N(2) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(3) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ni(1), one H(1), and one H(2) atom. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Ni(1), one H(3), and one H(4) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Ni(1), one H(5), and one H(6) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one C(1), one H(2), and one H(6) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Ni(1), one C(2), and one H(4) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(5) atom. In the seventh O site, O(7) is bonded in a single-bond geometry to one C(5) atom. Linkers: 4 [O]C(=O)C1=NC(=O)NC(=O)[CH]1. Metal clusters: 4 [Ni]. The MOF has largest included sphere 1.94 A, density 2.07 g/cm3, surface area 3526.05 m2/g, accessible volume 0.10 cm3/g