CaCu(CO2)4(CH2)2 crystallizes in the orthorhombic Pbcn space group. The structure consists of eight 02329_fluka molecules inside a CaCu(CO2)4 framework. In the CaCu(CO2)4 framework, Ca(1) is bonded in a distorted octahedral geometry to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms. Both Ca(1)-O(2) bond lengths are 2.36 Å. Both Ca(1)-O(3) bond lengths are 2.72 Å. Both Ca(1)-O(4) bond lengths are 2.45 Å. Cu(1) is bonded in a square co-planar geometry to two equivalent O(1) and two equivalent O(3) atoms. Both Cu(1)-O(1) bond lengths are 1.96 Å. Both Cu(1)-O(3) bond lengths are 1.94 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 O(1) and one O(2) atom. The C(1)-O(1) bond length is 1.26 Å. The C(1)-O(2) bond length is 1.24 Å. In the second C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(4) atom. The C(3)-O(3) bond length is 1.27 Å. The C(3)-O(4) bond length is 1.24 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Cu(1) and one C(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Ca(1) and one C(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Ca(1), one Cu(1), and one C(3) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one Ca(1) and one C(3) atom. Linkers: 8 [O]C(=O)CC([O])=O. Metal clusters: 4 [Ca] ,4 [Cu]. The MOF has largest included sphere 3.80 A, density 1.69 g/cm3, surface area 3258.30 m2/g, accessible volume 0.21 cm3/g