Fe4O(PO4)4 crystallizes in the tetragonal I-42m space group. Fe(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form FeO5 trigonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra and corners with three equivalent Fe(1)O5 trigonal bipyramids. The Fe(1)-O(2) bond length is 2.16 Å. The Fe(1)-O(3) bond length is 2.00 Å. The Fe(1)-O(4) bond length is 1.84 Å. Both Fe(1)-O(1) bond lengths are 1.96 Å. P(1) is bonded to one O(3), one O(4), and two equivalent O(1) atoms to form PO4 tetrahedra that share corners with four equivalent Fe(1)O5 trigonal bipyramids. The P(1)-O(3) bond length is 1.48 Å. The P(1)-O(4) bond length is 1.64 Å. Both P(1)-O(1) bond lengths are 1.53 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(1) atom. In the second O site, O(2) is bonded in a tetrahedral geometry to four equivalent Fe(1) atoms. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. Linkers: 8 [O]P([O])([O])=O. Metal clusters: 8 [Fe]. The MOF has largest included sphere 4.32 A, density 2.08 g/cm3, surface area 2104.99 m2/g, accessible volume 0.23 cm3/g