HgC5H3(NO)2 is Indium-like structured and crystallizes in the monoclinic Cc space group. The structure is zero-dimensional and consists of four HgC5H3(NO)2 clusters. There are two inequivalent Hg sites. In the first Hg site, Hg(1) is bonded in a 3-coordinate geometry to one N(1), one N(4), and one O(1) atom. The Hg(1)-N(1) bond length is 2.61 Å. The Hg(1)-N(4) bond length is 2.42 Å. The Hg(1)-O(1) bond length is 2.33 Å. In the second Hg site, Hg(2) is bonded in a single-bond geometry to one O(4) atom. The Hg(2)-O(4) bond length is 2.26 Å. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(3), one N(4), and one H(1) atom. The C(1)-C(3) bond length is 1.39 Å. The C(1)-N(4) bond length is 1.34 Å. The C(1)-H(1) bond length is 1.09 Å. In the second C site, C(2) is bonded in a distorted trigonal planar geometry to one C(3), one C(9), and one N(3) atom. The C(2)-C(3) bond length is 1.39 Å. The C(2)-C(9) bond length is 1.53 Å. The C(2)-N(3) bond length is 1.35 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(1), one C(2), and one H(2) atom. The C(3)-H(2) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted trigonal planar geometry to one C(10), one C(5), and one N(1) atom. The C(4)-C(10) bond length is 1.52 Å. The C(4)-C(5) bond length is 1.40 Å. The C(4)-N(1) bond length is 1.34 Å. In the fifth C site, C(5) is bonded in a distorted trigonal planar geometry to one C(4), one C(7), and one H(3) atom. The C(5)-C(7) bond length is 1.39 Å. The C(5)-H(3) bond length is 1.09 Å. In the sixth C site, C(6) is bonded in a trigonal planar geometry to one N(1), one N(2), and one H(4) atom. The C(6)-N(1) bond length is 1.34 Å. The C(6)-N(2) bond length is 1.34 Å. The C(6)-H(4) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(5), one N(2), and one H(5) atom. The C(7)-N(2) bond length is 1.34 Å. The C(7)-H(5) bond length is 1.09 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one N(3), one N(4), and one H(6) atom. The C(8)-N(3) bond length is 1.33 Å. The C(8)-N(4) bond length is 1.35 Å. The C(8)-H(6) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(3), and one O(4) atom. The C(9)-O(3) bond length is 1.26 Å. The C(9)-O(4) bond length is 1.28 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(1), and one O(2) atom. The C(10)-O(1) bond length is 1.29 Å. The C(10)-O(2) bond length is 1.25 Å. There are four inequivalent N sites. In the first N site, N(1) is bonded in a distorted bent 120 degrees geometry to one Hg(1), one C(4), and one C(6) atom. In the second N site, N(2) is bonded in a bent 120 degrees geometry to one C(6) and one C(7) atom. In the third N site, N(3) is bonded in a bent 120 degrees geometry to one C(2) and one C(8) atom. In the fourth N site, N(4) is bonded in a distorted trigonal planar geometry to one Hg(1), one C(1), and one C(8) atom. There are six 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(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(7) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(8) atom. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Hg(1) and one C(10) atom. In the second O site, O(2) is bonded in a single-bond geometry to one C(10) atom. In the third O site, O(3) is bonded in a single-bond geometry to one C(9) atom. In the fourth O site, O(4) is bonded in a distorted bent 120 degrees geometry to one Hg(2) and one C(9) atom. Linkers: 4 [O]C(=O)c1ccncn1. Metal clusters: 4 [Hg]. The MOF has largest included sphere 2.45 A, density 3.29 g/cm3, surface area 2291.95 m2/g, accessible volume 0.07 cm3/g