NiC5N2H5O3Cl crystallizes in the orthorhombic Pna2_1 space group. Ni(1) is bonded in an octahedral geometry to one N(1), one N(2), one O(1), one O(2), one O(3), and one Cl(1) atom. The Ni(1)-N(1) bond length is 2.01 Å. The Ni(1)-N(2) bond length is 1.99 Å. The Ni(1)-O(1) bond length is 2.10 Å. The Ni(1)-O(2) bond length is 2.17 Å. The Ni(1)-O(3) bond length is 2.06 Å. The Ni(1)-Cl(1) bond length is 2.43 Å. There are five inequivalent C sites. In the first C site, C(3) is bonded in a distorted trigonal planar geometry to one C(1), one C(4), and one N(1) atom. The C(3)-C(1) bond length is 1.49 Å. The C(3)-C(4) bond length is 1.39 Å. The C(3)-N(1) bond length is 1.35 Å. In the second C site, C(4) is bonded in a distorted trigonal planar geometry to one C(3), one N(2), and one H(4) atom. The C(4)-N(2) bond length is 1.34 Å. The C(4)-H(4) bond length is 1.09 Å. In the third C site, C(5) is bonded in a distorted trigonal planar geometry to one C(2), one N(2), and one H(5) atom. The C(5)-C(2) bond length is 1.39 Å. The C(5)-N(2) bond length is 1.34 Å. The C(5)-H(5) bond length is 1.09 Å. In the fourth C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(3) atom. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(3) bond length is 1.26 Å. In the fifth C site, C(2) is bonded in a distorted trigonal planar geometry to one C(5), one N(1), and one H(3) atom. The C(2)-N(1) bond length is 1.34 Å. The C(2)-H(3) bond length is 1.09 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(2), and one C(3) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one Ni(1), one C(4), and one C(5) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(2) atom. The H(1)-O(2) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) atom. The H(2)-O(2) bond length is 0.99 Å. 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 C(4) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(5) atom. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted water-like geometry to one Ni(1), one H(1), and one H(2) atom. In the third O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(1) atom. Cl(1) is bonded in a single-bond geometry to one Ni(1) atom. Linkers: 4 [O]C(=O)c1cnccn1. Metal clusters: 4 [Ni]. The MOF has largest included sphere 3.26 A, density 1.79 g/cm3, surface area 3466.31 m2/g, accessible volume 0.17 cm3/g