CaZnH6(CO)10 crystallizes in the monoclinic P2/c space group. Ca(1) is bonded in a distorted pentagonal pyramidal geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(5) atoms. Both Ca(1)-O(2) bond lengths are 2.35 Å. Both Ca(1)-O(3) bond lengths are 2.38 Å. Both Ca(1)-O(5) bond lengths are 2.38 Å. Zn(1) is bonded in a tetrahedral geometry to two equivalent O(1) and two equivalent O(4) atoms. Both Zn(1)-O(1) bond lengths are 2.01 Å. Both Zn(1)-O(4) bond lengths are 1.96 Å. There are five inequivalent C sites. In the first C site, C(5) is bonded in a distorted single-bond geometry to one C(3), one C(4), and one H(3) atom. The C(5)-C(3) bond length is 1.39 Å. The C(5)-C(4) bond length is 1.40 Å. The C(5)-H(3) bond length is 1.09 Å. In the second C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(1), and one O(2) atom. The C(1)-C(3) bond length is 1.51 Å. The C(1)-O(1) bond length is 1.30 Å. The C(1)-O(2) bond length is 1.25 Å. In the third C site, C(2) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(3), and one O(4) atom. The C(2)-C(4) bond length is 1.49 Å. The C(2)-O(3) bond length is 1.26 Å. The C(2)-O(4) bond length is 1.29 Å. In the fourth C site, C(3) is bonded in a trigonal planar geometry to one C(1), one C(4), and one C(5) atom. The C(3)-C(4) bond length is 1.41 Å. In the fifth C site, C(4) is bonded in a trigonal planar geometry to one C(2), one C(3), and one C(5) atom. There are three inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(5) atom. The H(1)-O(5) bond length is 0.97 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(5) atom. The H(2)-O(5) bond length is 0.99 Å. In the third H site, H(3) is bonded in a single-bond geometry to one C(5) atom. There are five inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Zn(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one C(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(2) atom. In the fifth O site, O(5) is bonded in a distorted water-like geometry to one Ca(1), one H(1), and one H(2) atom. Linkers: 2 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1C([O])=O ,2 [O]C(=O)c1cc(C([O])=O)c(C([O])=O)cc1[C]=O. Metal clusters: 2 [Ca] ,2 [Zn]. The MOF has largest included sphere 2.96 A, density 2.09 g/cm3, surface area 2967.36 m2/g, accessible volume 0.10 cm3/g