TbH6(CO3)3 crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 9-coordinate geometry to one O(1), 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 Tb(1)-O(1) bond length is 2.51 Å. The Tb(1)-O(2) bond length is 2.54 Å. The Tb(1)-O(3) bond length is 2.36 Å. The Tb(1)-O(4) bond length is 2.47 Å. The Tb(1)-O(5) bond length is 2.41 Å. The Tb(1)-O(6) bond length is 2.38 Å. The Tb(1)-O(7) bond length is 2.42 Å. The Tb(1)-O(8) bond length is 2.41 Å. The Tb(1)-O(9) bond length is 2.47 Å. There are three inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(4) atom. The C(1)-O(2) bond length is 1.26 Å. The C(1)-O(4) bond length is 1.27 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(6) atom. The C(2)-O(1) bond length is 1.28 Å. The C(2)-O(6) bond length is 1.26 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(5) and one O(7) atom. The C(3)-O(5) bond length is 1.27 Å. The C(3)-O(7) bond length is 1.26 Å. There are six inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(3) atom. The H(1)-O(3) bond length is 0.98 Å. In the second H site, H(2) is bonded in a distorted linear geometry to one O(3) and one O(4) atom. The H(2)-O(3) bond length is 1.00 Å. The H(2)-O(4) bond length is 1.63 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. The H(3)-O(8) bond length is 0.97 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(8) atom. The H(4)-O(8) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(9) atom. The H(5)-O(9) bond length is 0.98 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one O(9) atom. The H(6)-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 Tb(1) and one C(2) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Tb(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Tb(1), one H(1), and one H(2) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Tb(1), one C(1), and one H(2) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Tb(1) and one C(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 120 degrees geometry to one Tb(1) and one C(2) atom. In the seventh O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Tb(1) and one C(3) atom. In the eighth O site, O(8) is bonded in a distorted water-like geometry to one Tb(1), one H(3), and one H(4) atom. In the ninth O site, O(9) is bonded in a water-like geometry to one Tb(1), one H(5), and one H(6) atom. Linkers: 6 [O]C(=O)C([O])=O. Metal clusters: 4 [Tb]. RCSR code: hcb. The MOF has largest included sphere 4.45 A, density 2.43 g/cm3, surface area 2208.12 m2/g, accessible volume 0.10 cm3/g