Sm2C18H9(NO4)3 crystallizes in the monoclinic P2/c space group. Sm(1) is bonded to one O(2), one O(3), one O(4), one O(5), one O(6), and two equivalent O(1) atoms to form distorted edge-sharing SmO7 pentagonal bipyramids. The Sm(1)-O(2) bond length is 2.30 Å. The Sm(1)-O(3) bond length is 2.38 Å. The Sm(1)-O(4) bond length is 2.38 Å. The Sm(1)-O(5) bond length is 2.30 Å. The Sm(1)-O(6) bond length is 2.37 Å. There is one shorter (2.43 Å) and one longer (2.56 Å) Sm(1)-O(1) bond length. There are ten inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal planar geometry to one C(4), one N(1), and one O(1) atom. The C(1)-C(4) bond length is 1.39 Å. The C(1)-N(1) bond length is 1.37 Å. The C(1)-O(1) bond length is 1.32 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one N(1) and one O(2) atom. The C(2)-N(1) bond length is 1.38 Å. The C(2)-O(2) bond length is 1.28 Å. In the third C site, C(3) is bonded in a distorted single-bond geometry to one C(5) and one H(1) atom. The C(3)-C(5) bond length is 1.39 Å. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(2) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-H(2) bond length is 1.08 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(3), one C(4), and one C(6) atom. The C(5)-C(6) bond length is 1.50 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(3), and one O(4) atom. The C(6)-O(3) bond length is 1.27 Å. The C(6)-O(4) bond length is 1.27 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(8), one N(2), and one O(5) atom. The C(7)-C(8) bond length is 1.40 Å. The C(7)-N(2) bond length is 1.38 Å. The C(7)-O(5) bond length is 1.29 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(7), one C(9), and one H(3) atom. The C(8)-C(9) bond length is 1.40 Å. The C(8)-H(3) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a trigonal planar geometry to one C(10) and two equivalent C(8) atoms. The C(9)-C(10) bond length is 1.50 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(9) and two equivalent O(6) atoms. Both C(10)-O(6) bond lengths are 1.27 Å. There are two inequivalent N sites. In the first N site, N(1) is bonded in a trigonal planar geometry to one C(1), one C(2), and one H(4) atom. The N(1)-H(4) bond length is 1.03 Å. In the second N site, N(2) is bonded in a trigonal planar geometry to two equivalent C(7) and one H(5) atom. The N(2)-H(5) bond length is 1.03 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(4) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(8) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one N(1) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one N(2) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Sm(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Sm(1) and one C(2) atom. In the third O site, O(3) is bonded in a distorted linear geometry to one Sm(1) and one C(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Sm(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Sm(1) and one C(7) atom. In the sixth O site, O(6) is bonded in a distorted linear geometry to one Sm(1) and one C(10) atom. Linkers: 6 [O]C(=O)C1=CC(=O)NC(=O)[CH]1. Metal clusters: 4 [Sm]. The MOF has largest included sphere 2.04 A, density 2.78 g/cm3, surface area 1902.81 m2/g, accessible volume 0.05 cm3/g