CoH3(CO2)3 crystallizes in the orthorhombic Imma space group. Co(1) is bonded in an octahedral geometry to two equivalent O(2) and four equivalent O(1) atoms. Both Co(1)-O(2) bond lengths are 2.14 Å. All Co(1)-O(1) bond lengths are 2.08 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one H(1) and two equivalent O(2) atoms. The C(1)-H(1) bond length is 0.93 Å. Both C(1)-O(2) bond lengths are 1.24 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one H(2) and two equivalent O(1) atoms. The C(2)-H(2) bond length is 0.93 Å. Both C(2)-O(1) bond lengths are 1.19 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. There are two inequivalent O sites. In the first O site, O(2) is bonded in a bent 120 degrees geometry to one Co(1) and one C(1) atom. In the second O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Co(1) and one C(2) atom. Linkers: 6 [O]C=O. Metal clusters: 2 [Co]. RCSR code: pcu. The MOF has largest included sphere 4.13 A, density 1.53 g/cm3, surface area 3459.71 m2/g, accessible volume 0.33 cm3/g