NaC4H7O7 crystallizes in the orthorhombic P2_12_12_1 space group. Na(1) is bonded in a 7-coordinate geometry to one O(2), one O(4), one O(6), two equivalent O(1), and two equivalent O(3) atoms. The Na(1)-O(2) bond length is 2.48 Å. The Na(1)-O(4) bond length is 2.42 Å. The Na(1)-O(6) bond length is 2.42 Å. There is one shorter (2.53 Å) and one longer (2.58 Å) Na(1)-O(1) bond length. There is one shorter (2.61 Å) and one longer (2.63 Å) Na(1)-O(3) bond length. There are four inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one O(3) and one O(5) atom. The C(1)-O(3) bond length is 1.23 Å. The C(1)-O(5) bond length is 1.32 Å. In the second C site, C(2) is bonded in a distorted water-like geometry to one H(6) and one O(1) atom. The C(2)-H(6) bond length is 1.10 Å. The C(2)-O(1) bond length is 1.43 Å. In the third C site, C(3) is bonded in a distorted bent 120 degrees geometry to one O(2) and one O(7) atom. The C(3)-O(2) bond length is 1.25 Å. The C(3)-O(7) bond length is 1.29 Å. In the fourth C site, C(4) is bonded in a distorted water-like geometry to one H(7) and one O(6) atom. The C(4)-H(7) bond length is 1.10 Å. The C(4)-O(6) bond length is 1.41 Å. There are seven inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(4) atom. The H(1)-O(4) bond length is 0.99 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(2) and one O(4) atom. The H(2)-O(2) bond length is 1.70 Å. The H(2)-O(4) bond length is 1.00 Å. In the third H site, H(3) is bonded in a single-bond geometry to one O(1) atom. The H(3)-O(1) bond length is 0.98 Å. In the fourth H site, H(4) is bonded in a distorted linear geometry to one O(4) and one O(6) atom. The H(4)-O(4) bond length is 1.62 Å. The H(4)-O(6) bond length is 1.01 Å. In the fifth H site, H(5) is bonded in a linear geometry to one O(5) and one O(7) atom. The H(5)-O(5) bond length is 1.05 Å. The H(5)-O(7) bond length is 1.48 Å. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(2) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(4) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to two equivalent Na(1), one C(2), and one H(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Na(1), one C(3), and one H(2) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to two equivalent Na(1) and one C(1) atom. In the fourth O site, O(4) is bonded in a distorted water-like geometry to one Na(1), one H(1), one H(2), and one H(4) atom. In the fifth O site, O(5) is bonded in a water-like geometry to one C(1) and one H(5) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Na(1), one C(4), and one H(4) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one C(3) and one H(5) atom. Linkers: 4 [O]C(=O)[C@@H](O)[C@H](O)C(=O)O. Metal clusters: 4 [Na]. The MOF has largest included sphere 1.42 A, density 1.91 g/cm3, surface area 2488.06 m2/g, accessible volume 0.01 cm3/g