FePH5(CO3)2 crystallizes in the monoclinic P2_1/c space group. Fe(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form FeO6 octahedra that share corners with three equivalent P(1)CO3 tetrahedra. The Fe(1)-O(1) bond length is 1.95 Å. The Fe(1)-O(2) bond length is 1.89 Å. The Fe(1)-O(3) bond length is 1.98 Å. The Fe(1)-O(4) bond length is 2.17 Å. The Fe(1)-O(5) bond length is 2.14 Å. The Fe(1)-O(6) bond length is 2.10 Å. There are two inequivalent C sites. In the first C site, C(2) is bonded in a distorted bent 120 degrees geometry to one O(4) and one O(5) atom. The C(2)-O(4) bond length is 1.27 Å. The C(2)-O(5) bond length is 1.26 Å. In the second C site, C(1) is bonded in a distorted tetrahedral geometry to one P(1), one H(1), one H(2), and one H(3) atom. The C(1)-P(1) bond length is 1.79 Å. The C(1)-H(1) bond length is 1.10 Å. The C(1)-H(2) bond length is 1.10 Å. The C(1)-H(3) bond length is 1.10 Å. P(1) is bonded to one C(1), one O(1), one O(2), and one O(3) atom to form PCO3 tetrahedra that share corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 15-45°. The P(1)-O(1) bond length is 1.53 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.56 Å. There are five 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. In the third H site, H(3) is bonded in a single-bond geometry to one C(1) atom. In the fourth H site, H(4) is bonded in a distorted single-bond geometry to one O(4) and one O(6) atom. The H(4)-O(4) bond length is 1.65 Å. The H(4)-O(6) bond length is 1.00 Å. In the fifth H site, H(5) is bonded in a single-bond geometry to one O(3) and one O(6) atom. The H(5)-O(3) bond length is 1.74 Å. The H(5)-O(6) bond length is 1.00 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to one Fe(1) and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Fe(1), one P(1), and one H(5) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Fe(1), one C(2), and one H(4) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Fe(1) and one C(2) atom. In the sixth O site, O(6) is bonded in a distorted water-like geometry to one Fe(1), one H(4), and one H(5) atom. Linkers: 1 [O]C(=O)C([O])=O. Metal clusters: 4 [Fe]. The MOF has largest included sphere 1.96 A, density 2.25 g/cm3, surface area 2888.36 m2/g, accessible volume 0.05 cm3/g