Al4P4O17 crystallizes in the orthorhombic Pbcm space group. There are three inequivalent Al sites. In the first Al site, Al(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form AlO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra and corners with two equivalent P(1)O4 tetrahedra. The Al(1)-O(1) bond length is 1.92 Å. The Al(1)-O(2) bond length is 1.91 Å. The Al(1)-O(4) bond length is 1.90 Å. The Al(1)-O(5) bond length is 1.89 Å. In the second Al site, Al(2) is bonded to one O(10), one O(9), and two equivalent O(3) atoms to form AlO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra and corners with two equivalent P(1)O4 tetrahedra. The Al(2)-O(10) bond length is 1.90 Å. The Al(2)-O(9) bond length is 1.85 Å. Both Al(2)-O(3) bond lengths are 1.95 Å. In the third Al site, Al(3) is bonded in a 5-coordinate geometry to one O(8), two equivalent O(6), and two equivalent O(7) atoms. The Al(3)-O(8) bond length is 1.83 Å. Both Al(3)-O(6) bond lengths are 1.77 Å. Both Al(3)-O(7) bond lengths are 1.79 Å. There are three inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(3), one O(4), and one O(6) atom to form PO4 tetrahedra that share  a cornercorner with one Al(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. The P(1)-O(1) bond length is 1.51 Å. The P(1)-O(3) bond length is 1.47 Å. The P(1)-O(4) bond length is 1.47 Å. The P(1)-O(6) bond length is 1.49 Å. In the second P site, P(2) is bonded in a 5-coordinate geometry to one O(10), two equivalent O(5), and two equivalent O(7) atoms. The P(2)-O(10) bond length is 1.51 Å. Both P(2)-O(5) bond lengths are 1.40 Å. Both P(2)-O(7) bond lengths are 1.50 Å. In the third P site, P(3) is bonded to one O(8), one O(9), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Al(2)O4 tetrahedra and corners with two equivalent Al(1)O4 tetrahedra. The P(3)-O(8) bond length is 1.52 Å. The P(3)-O(9) bond length is 1.51 Å. Both P(3)-O(2) bond lengths are 1.50 Å. There are ten inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 120 degrees geometry to one Al(1) and one P(1) 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 bent 150 degrees geometry to one Al(2) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1) and one P(1) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Al(1) and one P(2) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Al(3) and one P(1) atom. In the seventh O site, O(7) is bonded in a 3-coordinate geometry to one Al(3), one P(2), and one O(7) atom. The O(7)-O(7) bond length is 1.00 Å. In the eighth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Al(2) and one P(3) atom. In the ninth O site, O(10) is bonded in a bent 150 degrees geometry to one Al(2) and one P(2) atom. In the tenth O site, O(8) is bonded in a bent 120 degrees geometry to one Al(3) and one P(3) atom. Linkers: 4 [O].[O]OP(=O)=O. Metal clusters: 16 [Al]. The MOF has largest included sphere 4.97 A, density 1.70 g/cm3, surface area 2671.16 m2/g, accessible volume 0.26 cm3/g