YbH27(C17O2)3(CH)12 crystallizes in the trigonal P-3m1 space group. The structure consists of twenty-four 02329_fluka molecules inside a YbH27(C17O2)3 framework. In the YbH27(C17O2)3 framework, there are two inequivalent Yb sites. In the first Yb site, Yb(1) is bonded in an octahedral geometry to six equivalent O(1) atoms. All Yb(1)-O(1) bond lengths are 2.19 Å. In the second Yb site, Yb(2) is bonded in an octahedral geometry to six equivalent O(2) atoms. All Yb(2)-O(2) bond lengths are 2.19 Å. There are eleven inequivalent C sites. In the first C site, C(9) is bonded in a distorted trigonal planar geometry to one C(10), one O(1), and one O(2) atom. The C(9)-C(10) bond length is 1.48 Å. The C(9)-O(1) bond length is 1.26 Å. The C(9)-O(2) bond length is 1.25 Å. In the second C site, C(10) is bonded in a 5-coordinate geometry to one C(9), two equivalent C(1), and two equivalent C(8) atoms. Both C(10)-C(1) bond lengths are 1.43 Å. Both C(10)-C(8) bond lengths are 1.48 Å. In the third C site, C(11) is bonded in a 6-coordinate geometry to two equivalent C(1), two equivalent C(5), and two equivalent C(6) atoms. Both C(11)-C(1) bond lengths are 1.48 Å. Both C(11)-C(5) bond lengths are 1.40 Å. Both C(11)-C(6) bond lengths are 1.34 Å. In the fourth C site, C(12) is bonded in a 4-coordinate geometry to two equivalent C(13) and two equivalent C(5) atoms. Both C(12)-C(13) bond lengths are 1.38 Å. Both C(12)-C(5) bond lengths are 1.58 Å. In the fifth C site, C(13) is bonded in a single-bond geometry to two equivalent C(12) and one H(7) atom. The C(13)-H(7) bond length is 0.95 Å. In the sixth C site, C(1) is bonded in a 4-coordinate geometry to one C(1), one C(10), one C(11), and one C(2) atom. The C(1)-C(1) bond length is 0.83 Å. The C(1)-C(2) bond length is 1.31 Å. In the seventh C site, C(2) is bonded in a distorted single-bond geometry to one C(1) and one H(1) atom. The C(2)-H(1) bond length is 0.95 Å. In the eighth C site, C(4) is bonded in a distorted single-bond geometry to one C(5) and one H(3) atom. The C(4)-C(5) bond length is 1.37 Å. The C(4)-H(3) bond length is 0.95 Å. In the ninth C site, C(5) is bonded in a 4-coordinate geometry to one C(11), one C(12), one C(4), and one C(5) atom. The C(5)-C(5) bond length is 1.10 Å. In the tenth C site, C(6) is bonded in a distorted single-bond geometry to one C(11) and one H(4) atom. The C(6)-H(4) bond length is 0.96 Å. In the eleventh C site, C(8) is bonded in a distorted single-bond geometry to one C(10) and one H(6) atom. The C(8)-H(6) bond length is 0.96 Å. There are five inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one C(2) and one H(1) atom. The H(1)-H(1) bond length is 0.97 Å. In the second H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the third H site, H(4) is bonded in a single-bond geometry to one C(6) atom. In the fourth H site, H(6) is bonded in a single-bond geometry to one C(8) atom. In the fifth H site, H(7) is bonded in a single-bond geometry to one C(13) atom. There are two inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Yb(1) and one C(9) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Yb(2) and one C(9) atom. Linkers: 1 [C][C]1[C]/C=C\[CH][C]2[C@@]3([C@@H]4[CH][CH][CH][CH][C@@H]43)[C@@]2(c2cc([C@]34[CH]/C=C\[C]([C])[C]/C=C\[CH][C]3[C@@]43[C@@H]4[CH][CH][CH][CH][C@@H]43)cc([C@@]34[CH]/C=C\[C]([C])[C]/C=C\[CH][C]3[C@]43[C@@H]4[CH][CH][CH][CH][C@@H]43)c2)[CH]/C=C\1.[O][C]=O.[O][C]=O.[O][C]=O ,1 [C][C]1[C]/C=C\[CH][C@@]2(c3cc([C@]45[CH]/C=C\[C][C]([C])/C=C\[CH][C]4[C@]54[C@@H]5[CH][CH][CH][CH][C@@H]54)cc([C@@]45[CH]/C=C\[C][C]([C])/C=C\[CH][C]4[C@]54[C@@H]5[CH][CH][CH][CH][C@@H]54)c3)[C]([CH]/C=C\1)[C@@]21[C@@H]2[CH][CH][CH][CH][C@@H]21.[O][C]=O.[O][C]=O.[O][C]=O. Metal clusters: 2 [Yb]. RCSR code: nia. The MOF has largest included sphere 5.46 A, density 1.52 g/cm3, surface area 2990.93 m2/g, accessible volume 0.28 cm3/g