Fe3B2P4(HO5)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(1), one O(10), one O(5), one O(8), and one O(9) atom to form FeO5 square pyramids that share  a cornercorner with one B(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra, and corners with three equivalent P(1)O4 tetrahedra. The Fe(1)-O(1) bond length is 2.03 Å. The Fe(1)-O(10) bond length is 1.94 Å. The Fe(1)-O(5) bond length is 1.99 Å. The Fe(1)-O(8) bond length is 2.00 Å. The Fe(1)-O(9) bond length is 1.91 Å. In the second Fe site, Fe(2) is bonded to two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms to form FeO6 octahedra that share corners with two equivalent B(1)O4 tetrahedra and corners with four equivalent P(2)O4 tetrahedra. Both Fe(2)-O(3) bond lengths are 2.03 Å. Both Fe(2)-O(6) bond lengths are 2.08 Å. Both Fe(2)-O(7) bond lengths are 1.92 Å. B(1) is bonded to one O(1), one O(2), one O(4), and one O(6) atom to form BO4 tetrahedra that share  a cornercorner with one Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O5 square pyramid,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 48°. The B(1)-O(1) bond length is 1.47 Å. The B(1)-O(2) bond length is 1.48 Å. The B(1)-O(4) bond length is 1.48 Å. The B(1)-O(6) bond length is 1.47 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(10), one O(2), one O(5), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Fe(1)O5 square pyramids and  a cornercorner with one B(1)O4 tetrahedra. The P(1)-O(10) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(5) bond length is 1.53 Å. The P(1)-O(8) bond length is 1.54 Å. In the second P site, P(2) is bonded to one O(3), one O(4), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Fe(1)O5 square pyramid, and  a cornercorner with one B(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 48-55°. The P(2)-O(3) bond length is 1.52 Å. The P(2)-O(4) bond length is 1.56 Å. The P(2)-O(7) bond length is 1.52 Å. The P(2)-O(9) bond length is 1.52 Å. There are two inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one O(6) atom. The H(1)-O(6) bond length is 0.70 Å. In the second H site, H(2) is bonded in a single-bond geometry to one O(1) atom. The H(2)-O(1) bond length is 0.82 Å. There are ten inequivalent O sites. In the first O site, O(7) is bonded in a distorted bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the second O site, O(8) is bonded in a 2-coordinate geometry to one Fe(1) and one P(1) atom. In the third O site, O(9) is bonded in a distorted linear geometry to one Fe(1) and one P(2) atom. In the fourth O site, O(10) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the fifth O site, O(1) is bonded in a 3-coordinate geometry to one Fe(1), one B(1), and one H(2) atom. In the sixth O site, O(2) is bonded in a bent 120 degrees geometry to one B(1) and one P(1) atom. In the seventh O site, O(3) is bonded in a bent 120 degrees geometry to one Fe(2) and one P(2) atom. In the eighth O site, O(4) is bonded in a bent 120 degrees geometry to one B(1) and one P(2) atom. In the ninth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Fe(1) and one P(1) atom. In the tenth O site, O(6) is bonded in a 3-coordinate geometry to one Fe(2), one B(1), and one H(1) atom. Linkers: 4 O[B](OP(=O)([O])[O])(OP(=O)([O])[O])O. Metal clusters: 6 [Fe]. The MOF has largest included sphere 4.52 A, density 2.31 g/cm3, surface area 2168.99 m2/g, accessible volume 0.10 cm3/g