YbH12(C4O3)3 crystallizes in the triclinic P-1 space group. Yb(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(5), one O(6), one O(7), one O(8), and one O(9) atom. The Yb(1)-O(2) bond length is 2.22 Å. The Yb(1)-O(3) bond length is 2.23 Å. The Yb(1)-O(4) bond length is 2.23 Å. The Yb(1)-O(5) bond length is 2.47 Å. The Yb(1)-O(6) bond length is 2.37 Å. The Yb(1)-O(7) bond length is 2.32 Å. The Yb(1)-O(8) bond length is 2.43 Å. The Yb(1)-O(9) bond length is 2.33 Å. There are twelve 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 1.49 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(8) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-C(8) 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) and one H(1) atom. 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(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 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one C(7) atom. The C(5)-C(6) bond length is 1.50 Å. The C(5)-C(7) bond length is 1.40 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(5), one C(8), and one H(3) atom. The C(7)-C(8) bond length is 1.39 Å. The C(7)-H(3) bond length is 1.09 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(2), one C(7), and one H(4) atom. The C(8)-H(4) bond length is 1.09 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(10), one O(5), and one O(6) atom. The C(9)-C(10) bond length is 1.49 Å. The C(9)-O(5) bond length is 1.27 Å. The C(9)-O(6) bond length is 1.29 Å. In the tenth C site, C(10) is bonded in a trigonal planar geometry to one C(11), one C(12), and one C(9) atom. The C(10)-C(11) bond length is 1.40 Å. The C(10)-C(12) bond length is 1.40 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(10) and one H(5) atom. The C(11)-H(5) bond length is 1.09 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(10) and one H(6) atom. The C(12)-H(6) bond length is 1.09 Å. There are twelve 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(7) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(8) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(11) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(12) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(7) atom. The H(7)-O(7) bond length is 0.98 Å. In the eighth H site, H(8) is bonded in a distorted linear geometry to one O(5) and one O(7) atom. The H(8)-O(5) bond length is 1.64 Å. The H(8)-O(7) bond length is 1.00 Å. In the ninth H site, H(9) is bonded in a single-bond geometry to one O(1) and one O(8) atom. The H(9)-O(1) bond length is 1.71 Å. The H(9)-O(8) bond length is 1.00 Å. In the tenth H site, H(10) is bonded in a single-bond geometry to one O(8) atom. The H(10)-O(8) bond length is 0.99 Å. In the eleventh H site, H(11) is bonded in a single-bond geometry to one O(9) atom. The H(11)-O(9) bond length is 0.99 Å. In the twelfth H site, H(12) is bonded in a distorted single-bond geometry to one O(1) and one O(9) atom. The H(12)-O(1) bond length is 1.69 Å. The H(12)-O(9) bond length is 1.00 Å. There are nine inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one C(1), one H(12), and one H(9) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Yb(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Yb(1) and one C(6) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Yb(1) and one C(6) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to one Yb(1), one C(9), and one H(8) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one Yb(1) and one C(9) atom. In the seventh O site, O(7) is bonded in a distorted water-like geometry to one Yb(1), one H(7), and one H(8) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Yb(1), one H(10), and one H(9) atom. In the ninth O site, O(9) is bonded in a distorted water-like geometry to one Yb(1), one H(11), and one H(12) atom. Linkers: 1 [O]C(=O)c1ccc([C]=O)cc1 ,2 [O]C(=O)c1ccc(C([O])=O)cc1. Metal clusters: 1 O.O.O.O.O.O.O=[C]O[Yb]1(O[C]=O)O[C]O[Yb](O[C]=O)(O[C]=O)O[C]O1. RCSR code: sql. The MOF has largest included sphere 2.00 A, density 2.33 g/cm3, surface area 2911.70 m2/g, accessible volume 0.10 cm3/g