NiC5H5(NO)2 crystallizes in the monoclinic P2_1/c space group. Ni(1) is bonded in a rectangular see-saw-like geometry to one N(1), one N(2), one O(1), and one O(2) atom. The Ni(1)-N(1) bond length is 2.12 Å. The Ni(1)-N(2) bond length is 2.11 Å. The Ni(1)-O(1) bond length is 2.04 Å. The Ni(1)-O(2) bond length is 2.06 Å. There are five inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(2), one N(1), and one H(1) atom. The C(1)-C(2) bond length is 1.38 Å. The C(1)-N(1) bond length is 1.33 Å. The C(1)-H(1) bond length is 0.93 Å. In the second C site, C(2) is bonded in a 3-coordinate geometry to one C(1), one N(1), and one H(2) atom. The C(2)-N(1) bond length is 1.33 Å. The C(2)-H(2) bond length is 0.93 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(4), one N(2), and one H(3) atom. The C(3)-C(4) bond length is 1.38 Å. The C(3)-N(2) bond length is 1.34 Å. The C(3)-H(3) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a distorted bent 120 degrees geometry to one C(3), one N(2), and one H(4) atom. The C(4)-N(2) bond length is 1.33 Å. The C(4)-H(4) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one H(5), one O(1), and one O(2) atom. The C(5)-H(5) bond length is 0.93 Å. The C(5)-O(1) bond length is 1.23 Å. The C(5)-O(2) bond length is 1.25 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(2) atom. In the second N site, N(2) is bonded in a trigonal planar geometry to one Ni(1), one C(3), and one C(4) atom. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(3) 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 two inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Ni(1) and one C(5) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ni(1) and one C(5) atom. Linkers: 4 c1cnccn1. Metal clusters: 4 [Ni]. The MOF has largest included sphere 4.10 A, density 1.44 g/cm3, surface area 4100.08 m2/g, accessible volume 0.33 cm3/g