Tb(OH)CO3 crystallizes in the orthorhombic P2_12_12_1 space group. Tb(1) is bonded in a 9-coordinate geometry to two equivalent O(1), two equivalent O(2), two equivalent O(4), and three equivalent O(3) atoms. There is one shorter (2.28 Å) and one longer (2.30 Å) Tb(1)-O(1) bond length. There is one shorter (2.42 Å) and one longer (2.43 Å) Tb(1)-O(2) bond length. There is one shorter (2.45 Å) and one longer (2.51 Å) Tb(1)-O(4) bond length. There are a spread of Tb(1)-O(3) bond distances ranging from 2.50-2.67 Å. C(1) is bonded in a trigonal planar geometry to one O(2), one O(3), and one O(4) atom. The C(1)-O(2) bond length is 1.29 Å. The C(1)-O(3) bond length is 1.30 Å. The C(1)-O(4) bond length is 1.29 Å. H(1) is bonded in a single-bond geometry to one O(1) atom. The H(1)-O(1) bond length is 0.98 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to two equivalent Tb(1) and one H(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent Tb(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to three equivalent Tb(1) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Tb(1) and one C(1) atom. Linkers: 4 [O]C([O])=O ,4 [OH]. Metal clusters: 4 [Tb]. RCSR code: utp. The MOF has largest included sphere 1.11 A, density 5.44 g/cm3, surface area 553.30 m2/g, accessible volume 0.01 cm3/g