NaPH8(CO2)3 crystallizes in the monoclinic P2_1/c space group. Na(1) is bonded to one H(3), one O(1), one O(2), one O(3), one O(6), and two equivalent O(5) atoms to form distorted NaHO6 pentagonal bipyramids that share  a cornercorner with one C(2)PC2O tetrahedra, corners with two equivalent P(1)HCO2 tetrahedra, and  an edgeedge with one Na(1)HO6 pentagonal bipyramid. The Na(1)-H(3) bond length is 2.49 Å. The Na(1)-O(1) bond length is 2.34 Å. The Na(1)-O(2) bond length is 2.37 Å. The Na(1)-O(3) bond length is 2.49 Å. The Na(1)-O(6) bond length is 2.51 Å. There is one shorter (2.32 Å) and one longer (2.36 Å) Na(1)-O(5) bond length. There are three inequivalent C sites. In the first C site, C(1) is bonded in a distorted bent 120 degrees geometry to one C(2), one O(4), and one O(5) atom. The C(1)-C(2) bond length is 1.52 Å. The C(1)-O(4) bond length is 1.33 Å. The C(1)-O(5) bond length is 1.23 Å. In the second C site, C(2) is bonded to one C(1), one C(3), one P(1), and one O(3) atom to form distorted CPC2O tetrahedra that share  a cornercorner with one Na(1)HO6 pentagonal bipyramid. The C(2)-C(3) bond length is 1.53 Å. The C(2)-P(1) bond length is 1.89 Å. The C(2)-O(3) bond length is 1.43 Å. In the third C site, C(3) is bonded in a trigonal non-coplanar geometry to one C(2), one H(2), one H(3), and one H(5) atom. The C(3)-H(2) bond length is 1.10 Å. The C(3)-H(3) bond length is 1.09 Å. The C(3)-H(5) bond length is 1.10 Å. P(1) is bonded to one C(2), one H(1), one O(1), and one O(2) atom to form distorted PHCO2 tetrahedra that share corners with two equivalent Na(1)HO6 pentagonal bipyramids. The P(1)-H(1) bond length is 1.42 Å. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.52 Å. There are eight inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one P(1) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(3) atom. In the third H site, H(3) is bonded in a single-bond geometry to one Na(1) and one C(3) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one O(3) atom. The H(4)-O(3) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(3) atom. In the sixth H site, H(6) is bonded in a linear geometry to one O(1) and one O(4) atom. The H(6)-O(1) bond length is 1.53 Å. The H(6)-O(4) bond length is 1.04 Å. In the seventh H site, H(7) is bonded in a single-bond geometry to one O(2) and one O(6) atom. The H(7)-O(2) bond length is 1.72 Å. The H(7)-O(6) bond length is 1.00 Å. In the eighth H site, H(8) is bonded in a single-bond geometry to one O(6) atom. The H(8)-O(6) bond length is 0.99 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Na(1), one P(1), and one H(6) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Na(1), one P(1), and one H(7) atom. In the third O site, O(3) is bonded in a distorted water-like geometry to one Na(1), one C(2), and one H(4) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one C(1) and one H(6) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Na(1) and one C(1) atom. In the sixth O site, O(6) is bonded in a water-like geometry to one Na(1), one H(7), and one H(8) atom. Linkers: 1 C[C@@](O)(C(=O)O)[P@H]([O])=O ,1 C[C@](O)(C(=O)O)[P@H]([O])=O ,1 C[C@@](O)(C(=O)O)[P@@H]([O])=O ,1 C[C@](O)(C(=O)O)[P@@H]([O])=O. Metal clusters: 4 [Na]. The MOF has largest included sphere 1.53 A, density 1.81 g/cm3, surface area 3219.64 m2/g, accessible volume 0.09 cm3/g