LaH5(C4O3)2 crystallizes in the monoclinic P2_1/c space group. La(1) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(6), two equivalent O(2), two equivalent O(4), and two equivalent O(5) atoms. The La(1)-O(1) bond length is 2.69 Å. The La(1)-O(3) bond length is 2.50 Å. The La(1)-O(6) bond length is 2.55 Å. There is one shorter (2.59 Å) and one longer (2.64 Å) La(1)-O(2) bond length. There is one shorter (2.48 Å) and one longer (2.79 Å) La(1)-O(4) bond length. There is one shorter (2.45 Å) and one longer (2.46 Å) La(1)-O(5) bond length. There are eight 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 1.48 Å. The C(1)-O(1) bond length is 1.28 Å. The C(1)-O(2) bond length is 1.29 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 trigonal planar geometry to one C(2), one C(4), and one H(1) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-H(1) bond length is 1.09 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(3), one C(5), and one C(6) atom. The C(4)-C(5) bond length is 1.49 Å. The C(4)-C(6) bond length is 1.40 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(5)-O(3) bond length is 1.27 Å. The C(5)-O(4) bond length is 1.29 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(4) and one H(2) atom. The C(6)-H(2) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted single-bond geometry to one O(5) atom. The C(7)-O(5) bond length is 1.35 Å. In the eighth C site, C(8) is bonded in a distorted single-bond geometry to one C(2) and one H(3) atom. The C(8)-H(3) bond length is 1.09 Å. There are five 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(6) 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 distorted single-bond geometry to one O(1) and one O(6) atom. The H(4)-O(1) bond length is 1.68 Å. The H(4)-O(6) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(6) atom. The H(5)-O(6) bond length is 0.98 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one La(1), one C(1), and one H(4) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to two equivalent La(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one La(1) and one C(5) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent La(1) and one C(5) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to two equivalent La(1) and one C(7) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one La(1), one H(4), and one H(5) atom. Linkers: 4 [O]C(=O)c1cc([O])cc(C([O])=O)c1. Metal clusters: 4 [La]. The MOF has largest included sphere 1.93 A, density 2.64 g/cm3, surface area 2289.77 m2/g, accessible volume 0.05 cm3/g