HoC5H9(NO4)2 crystallizes in the monoclinic C2 space group. Ho(1) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Ho(1)-O(1) bond lengths are 2.33 Å. Both Ho(1)-O(2) bond lengths are 2.42 Å. Both Ho(1)-O(3) bond lengths are 2.31 Å. Both Ho(1)-O(4) bond lengths are 2.41 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one N(1), one H(3), and one O(1) atom. The C(1)-N(1) bond length is 1.32 Å. The C(1)-H(3) bond length is 1.10 Å. The C(1)-O(1) bond length is 1.26 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one H(4), one O(3), and one O(4) atom. The C(2)-H(4) bond length is 1.11 Å. The C(2)-O(3) bond length is 1.28 Å. The C(2)-O(4) bond length is 1.26 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one H(5) and two equivalent O(2) atoms. The C(3)-H(5) bond length is 1.10 Å. Both C(3)-O(2) bond lengths are 1.27 Å. N(1) is bonded in a trigonal planar geometry to one C(1), one H(1), and one H(2) atom. The N(1)-H(1) bond length is 1.03 Å. The N(1)-H(2) bond length is 1.02 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one N(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one N(1) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(1) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(2) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(3) 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 Ho(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ho(1) and one C(3) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Ho(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ho(1) and one C(2) atom. Linkers: 3 [O]C=O. Metal clusters: 1 [Ho]. The MOF has largest included sphere 1.41 A, density 2.62 g/cm3, surface area 2805.22 m2/g, accessible volume 0.05 cm3/g