ErC12H5(NO3)2(CH)2 crystallizes in the monoclinic C2/c space group. The structure consists of sixteen 02329_fluka molecules inside a ErC12H5(NO3)2 framework. In the ErC12H5(NO3)2 framework, Er(1) is bonded in a 6-coordinate geometry to one O(1), one O(3), one O(4), one O(5), and two equivalent O(2) atoms. The Er(1)-O(1) bond length is 2.40 Å. The Er(1)-O(3) bond length is 2.30 Å. The Er(1)-O(4) bond length is 2.24 Å. The Er(1)-O(5) bond length is 2.32 Å. There is one shorter (2.28 Å) and one longer (2.41 Å) Er(1)-O(2) bond length. There are twelve inequivalent C sites. In the first C site, C(1) is bonded in a bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.48 Å. The C(1)-O(1) bond length is 1.25 Å. The C(1)-O(2) bond length is 1.30 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(3), and one C(7) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(7) bond length is 1.40 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.37 Å. The C(3)-H(1) bond length is 0.93 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one N(1) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-N(1) bond length is 1.42 Å. In the fifth C site, C(5) is bonded in a distorted single-bond geometry to one C(4) and one H(2) atom. The C(5)-H(2) bond length is 0.93 Å. In the sixth C site, C(7) is bonded in a distorted single-bond geometry to one C(2) and one O(4) atom. The C(7)-O(4) bond length is 1.32 Å. In the seventh C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(9), one O(3), and one O(5) atom. The C(8)-C(9) bond length is 1.50 Å. The C(8)-O(3) bond length is 1.26 Å. The C(8)-O(5) bond length is 1.25 Å. In the eighth C site, C(9) is bonded in a trigonal planar geometry to one C(10), one C(14), and one C(8) atom. The C(9)-C(10) bond length is 1.41 Å. The C(9)-C(14) bond length is 1.38 Å. In the ninth C site, C(10) is bonded in a distorted single-bond geometry to one C(9) and one O(6) atom. The C(10)-O(6) bond length is 1.36 Å. In the tenth C site, C(12) is bonded in a distorted single-bond geometry to one C(13) and one H(5) atom. The C(12)-C(13) bond length is 1.39 Å. The C(12)-H(5) bond length is 0.93 Å. In the eleventh C site, C(13) is bonded in a distorted trigonal planar geometry to one C(12), one C(14), and one N(2) atom. The C(13)-C(14) bond length is 1.39 Å. The C(13)-N(2) bond length is 1.43 Å. In the twelfth C site, C(14) is bonded in a distorted single-bond geometry to one C(13), one C(9), and one H(6) atom. The C(14)-H(6) bond length is 0.93 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a distorted bent 120 degrees geometry to one C(4) and one N(1) atom. The N(1)-N(1) bond length is 1.26 Å. In the second N site, N(2) is bonded in a distorted bent 120 degrees geometry to one C(13) and one N(2) atom. The N(2)-N(2) bond length is 1.24 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(3) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(5) atom. In the third H site, H(5) is bonded in a single-bond geometry to one C(12) atom. In the fourth H site, H(6) is bonded in a single-bond geometry to one C(14) atom. In the fifth H site, H(7) is bonded in a single-bond geometry to one O(6) atom. The H(7)-O(6) bond length is 0.85 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted L-shaped geometry to one Er(1) and one C(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to two equivalent Er(1) and one C(1) atom. In the third O site, O(6) is bonded in a water-like geometry to one C(10) and one H(7) atom. In the fourth O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Er(1) and one C(8) atom. In the fifth O site, O(4) is bonded in a bent 120 degrees geometry to one Er(1) and one C(7) atom. In the sixth O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Er(1) and one C(8) atom. Linkers: 6 [O]C(=O)c1cc([N][N]c2ccc([O])c(C([O])=O)c2)ccc1[O] ,4 [O]C(=O)c1cc(/N=N/c2ccc(O)c(C([O])=O)c2)ccc1O. Metal clusters: 8 [Er]. The MOF has largest included sphere 5.80 A, density 1.49 g/cm3, surface area 3122.31 m2/g, accessible volume 0.34 cm3/g