ZnH4(CO3)2 crystallizes in the trigonal P3_121 space group. Zn(1) is bonded in an octahedral geometry to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms. Both Zn(1)-O(1) bond lengths are 2.14 Å. Both Zn(1)-O(2) bond lengths are 2.23 Å. Both Zn(1)-O(3) bond lengths are 2.02 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to two equivalent O(2) atoms. Both C(1)-O(2) bond lengths are 1.26 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to two equivalent O(1) atoms. Both C(2)-O(1) bond lengths are 1.27 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a distorted single-bond geometry to one O(2) and one O(3) atom. The H(1)-O(2) bond length is 1.66 Å. The H(1)-O(3) bond length is 0.99 Å. In the second H site, H(2) is bonded in a distorted single-bond geometry to one O(1) and one O(3) atom. The H(2)-O(1) bond length is 1.69 Å. The H(2)-O(3) bond length is 0.99 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted trigonal planar geometry to one Zn(1), one H(1), and one H(2) atom. In the second O site, O(1) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(2), and one H(2) atom. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Zn(1), one C(1), and one H(1) atom. Linkers: 3 [O]C(=O)C([O])=O. Metal clusters: 3 [Zn]. The MOF has largest included sphere 2.12 A, density 2.22 g/cm3, surface area 3163.98 m2/g, accessible volume 0.14 cm3/g