TbH4(C2O)6 crystallizes in the monoclinic P2_1/c space group. Tb(1) is bonded in a 7-coordinate geometry to one O(1), one O(2), one O(3), one O(5), one O(6), and two equivalent O(4) atoms. The Tb(1)-O(1) bond length is 2.50 Å. The Tb(1)-O(2) bond length is 2.62 Å. The Tb(1)-O(3) bond length is 2.45 Å. The Tb(1)-O(5) bond length is 2.34 Å. The Tb(1)-O(6) bond length is 2.28 Å. There is one shorter (2.46 Å) and one longer (2.52 Å) Tb(1)-O(4) bond length. There are twelve inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(4) atom. The C(1)-C(2) bond length is 1.38 Å. The C(1)-C(3) bond length is 1.52 Å. The C(1)-C(4) bond length is 1.39 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(1), one C(10), and one C(6) atom. The C(2)-C(10) bond length is 1.40 Å. The C(2)-C(6) bond length is 1.51 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(11), and one C(5) atom. The C(3)-C(11) bond length is 1.39 Å. The C(3)-C(5) bond length is 1.39 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(1), one C(7), and one H(4) atom. The C(4)-C(7) bond length is 1.38 Å. The C(4)-H(4) bond length is 0.93 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(11), one C(12), and one C(3) atom. The C(5)-C(11) bond length is 1.40 Å. The C(5)-C(12) bond length is 1.49 Å. In the sixth C site, C(6) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(5), and one O(6) atom. The C(6)-O(5) bond length is 1.25 Å. The C(6)-O(6) bond length is 1.25 Å. In the seventh C site, C(7) is bonded in a trigonal planar geometry to one C(4), one C(8), and one C(9) atom. The C(7)-C(8) bond length is 1.40 Å. The C(7)-C(9) bond length is 1.50 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(7) and one H(3) atom. The C(8)-H(3) bond length is 0.93 Å. In the ninth C site, C(9) is bonded in a distorted bent 120 degrees geometry to one C(7), one O(1), and one O(3) atom. The C(9)-O(1) bond length is 1.26 Å. The C(9)-O(3) bond length is 1.26 Å. In the tenth C site, C(10) is bonded in a distorted single-bond geometry to one C(2) and one H(2) atom. The C(10)-H(2) bond length is 0.93 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(1) atom. The C(11)-H(1) bond length is 0.93 Å. In the twelfth C site, C(12) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(2), and one O(4) atom. The C(12)-O(2) bond length is 1.25 Å. The C(12)-O(4) bond length is 1.28 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(11) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(10) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(8) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(4) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted L-shaped geometry to one Tb(1) and one C(9) atom. In the second O site, O(2) is bonded in a single-bond geometry to one Tb(1) and one C(12) atom. In the third O site, O(3) is bonded in a distorted L-shaped geometry to one Tb(1) and one C(9) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Tb(1) and one C(12) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Tb(1) and one C(6) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Tb(1) and one C(6) atom. Linkers: 2 [O]C(=O)c1ccc(C([O])=O)c(-c2cc(C([O])=O)c(-c3cc(C([O])=O)ccc3C([O])=O)cc2C([O])=O)c1. Metal clusters: 4 [Tb]. The MOF has largest included sphere 3.98 A, density 1.85 g/cm3, surface area 2736.41 m2/g, accessible volume 0.23 cm3/g