Al4(PO4)5 crystallizes in the orthorhombic Pbcn space group. There are two inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(2), one O(3), one O(5), and one O(7) atom to form AlO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Al(1)-O(2) bond length is 1.71 Å. The Al(1)-O(3) bond length is 1.74 Å. The Al(1)-O(5) bond length is 1.75 Å. The Al(1)-O(7) bond length is 1.76 Å. In the second Al site, Al(2) is bonded to one O(10), one O(4), one O(6), one O(8), and one O(9) atom to form AlO5 square pyramids that share corners with two equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Al(2)-O(10) bond length is 1.88 Å. The Al(2)-O(4) bond length is 1.84 Å. The Al(2)-O(6) bond length is 1.88 Å. The Al(2)-O(8) bond length is 1.89 Å. The Al(2)-O(9) bond length is 1.95 Å. There are three inequivalent P sites. In the first P site, P(3) is bonded to two equivalent O(1) and two equivalent O(2) atoms to form PO4 tetrahedra that share corners with two equivalent Al(1)O4 tetrahedra. Both P(3)-O(1) bond lengths are 1.49 Å. Both P(3)-O(2) bond lengths are 1.53 Å. In the second P site, P(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form PO4 tetrahedra that share corners with two equivalent Al(2)O5 square pyramids and corners with two equivalent Al(1)O4 tetrahedra. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.50 Å. The P(1)-O(5) bond length is 1.55 Å. The P(1)-O(6) bond length is 1.52 Å. In the third P site, P(2) is bonded to one O(10), one O(7), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with three equivalent Al(2)O5 square pyramids and  a cornercorner with one Al(1)O4 tetrahedra. The P(2)-O(10) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.54 Å. The P(2)-O(8) bond length is 1.51 Å. The P(2)-O(9) bond length is 1.53 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a single-bond geometry to one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Al(1) and one P(3) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Al(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a linear geometry to one Al(2) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 120 degrees geometry to one Al(1) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Al(2) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1) and one P(2) atom. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Al(2) and one P(2) atom. In the ninth O site, O(9) is bonded in a bent 150 degrees geometry to one Al(2) and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Al(2) and one P(2) atom. Linkers: 20 [O]P([O])([O])=O. Metal clusters: 16 [Al]. The MOF has largest included sphere 4.50 A, density 1.75 g/cm3, surface area 2872.77 m2/g, accessible volume 0.18 cm3/g