GaC4H3O5 crystallizes in the monoclinic C2/c space group. Ga(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form corner-sharing GaO6 octahedra. The corner-sharing octahedral tilt angles are 55°. Both Ga(1)-O(1) bond lengths are 2.03 Å. Both Ga(1)-O(2) bond lengths are 2.01 Å. Both Ga(1)-O(3) bond lengths are 1.92 Å. There are two 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 distorted trigonal planar geometry to one C(1), one C(2), and one H(2) atom. The C(2)-C(2) bond length is 1.34 Å. The C(2)-H(2) bond length is 1.09 Å. There are two 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 0.97 Å. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Ga(1) and one C(1) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Ga(1) and one C(1) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to two equivalent Ga(1) and one H(1) atom. Linkers: 2 [O]C(=O)/C=C/C([O])=O. Metal clusters: 2 [Ga]. RCSR code: lvt. The MOF has largest included sphere 5.72 A, density 1.30 g/cm3, surface area 3131.99 m2/g, accessible volume 0.47 cm3/g