ErH7(CO)8CH(CH2)2 crystallizes in the triclinic P-1 space group. The structure consists of two 02329_fluka molecules and four 02329_fluka molecules inside a ErH7(CO)8 framework. In the ErH7(CO)8 framework, Er(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(4), one O(7), one O(8), two equivalent O(5), and two equivalent O(6) atoms. The Er(1)-O(1) bond length is 2.25 Å. The Er(1)-O(3) bond length is 2.40 Å. The Er(1)-O(4) bond length is 2.48 Å. The Er(1)-O(7) bond length is 2.30 Å. The Er(1)-O(8) bond length is 2.32 Å. There is one shorter (2.35 Å) and one longer (2.63 Å) Er(1)-O(5) bond length. There is one shorter (2.45 Å) and one longer (2.46 Å) Er(1)-O(6) bond length. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(1), and one O(2) atom. The C(1)-C(2) bond length is 1.50 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.27 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 1.40 Å. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(8) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-C(8) bond length is 1.48 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 1.09 Å. In the sixth C site, C(7) is bonded in a distorted single-bond geometry to one C(2) and one H(4) atom. The C(7)-H(4) bond length is 1.09 Å. In the seventh C site, C(8) is bonded in a bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(8)-O(3) bond length is 1.26 Å. The C(8)-O(4) bond length is 1.30 Å. In the eighth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(6) atom. The C(9)-O(5) bond length is 1.27 Å. The C(9)-O(6) bond length is 1.29 Å. There are seven 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(4) is bonded in a single-bond geometry to one C(7) atom. In the fourth H site, H(9) is bonded in a distorted linear geometry to one O(4) and one O(7) atom. The H(9)-O(4) bond length is 1.64 Å. The H(9)-O(7) bond length is 0.99 Å. In the fifth H site, H(10) is bonded in a single-bond geometry to one O(4) and one O(8) atom. The H(10)-O(4) bond length is 1.72 Å. The H(10)-O(8) bond length is 0.99 Å. In the sixth H site, H(11) is bonded in a distorted linear geometry to one O(2) and one O(7) atom. The H(11)-O(2) bond length is 1.63 Å. The H(11)-O(7) bond length is 1.00 Å. In the seventh H site, H(12) is bonded in a single-bond geometry to one O(2) and one O(8) atom. The H(12)-O(2) bond length is 1.69 Å. The H(12)-O(8) bond length is 1.00 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees 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 one C(1), one H(11), and one H(12) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one Er(1) and one C(8) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Er(1), one C(8), one H(10), and one H(9) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to two equivalent Er(1) and one C(9) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Er(1) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Er(1), one H(11), and one H(9) atom. In the eighth O site, O(8) is bonded in a distorted bent 120 degrees geometry to one Er(1), one H(10), and one H(12) atom. Linkers: 2 [O]C(=O)c1cccc(C([O])=O)c1 ,1 [O]C(=O)CCCCC([O])=O. Metal clusters: 2 [Er]. RCSR code: bex. The MOF has largest included sphere 2.80 A, density 2.35 g/cm3, surface area 2711.40 m2/g, accessible volume 0.08 cm3/g