NaCaC6NH6O6 crystallizes in the cubic P2_13 space group. Na(1) is bonded in an octahedral geometry to three equivalent O(1) and three equivalent O(2) atoms. All Na(1)-O(1) bond lengths are 2.41 Å. All Na(1)-O(2) bond lengths are 2.36 Å. Ca(1) is bonded in a 7-coordinate geometry to one N(1), three equivalent O(1), and three equivalent O(2) atoms. The Ca(1)-N(1) bond length is 2.68 Å. All Ca(1)-O(1) bond lengths are 2.43 Å. All Ca(1)-O(2) bond lengths are 2.37 Å. There are two inequivalent C sites. In the first C site, C(1) is bonded in a distorted trigonal non-coplanar geometry to one N(1), one H(1), and one H(2) atom. The C(1)-N(1) bond length is 1.46 Å. The C(1)-H(1) bond length is 1.10 Å. The C(1)-H(2) bond length is 1.10 Å. In the second C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(1) and one O(2) atom. The C(2)-O(1) bond length is 1.27 Å. The C(2)-O(2) bond length is 1.27 Å. N(1) is bonded in a distorted trigonal non-coplanar geometry to one Ca(1) and three equivalent C(1) atoms. 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(1) atom. There are two inequivalent O sites. In the first O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one Ca(1), and one C(2) atom. In the second O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Ca(1), and one C(2) atom. Linkers: 4 [O]C(=O)CN(CC([O])=O)CC([O])=O. Metal clusters: 4 [Na] ,4 [Ca]. The MOF has largest included sphere 2.01 A, density 1.85 g/cm3, surface area 2622.99 m2/g, accessible volume 0.07 cm3/g