MgAl7(PO4)8 is quartz (alpha)-derived structured and crystallizes in the monoclinic P2_1/m space group. Mg(1) is bonded to one O(14), one O(20), and two equivalent O(9) atoms to form MgO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(6)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The Mg(1)-O(14) bond length is 2.01 Å. The Mg(1)-O(20) bond length is 1.90 Å. Both Mg(1)-O(9) bond lengths are 1.91 Å. There are three inequivalent Al sites. In the first Al site, Al(1,2) is bonded to one O(1), one O(10), one O(6), and one O(8) atom to form AlO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(2)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(6)O4 tetrahedra. The Al(1,2)-O(1) bond length is 1.77 Å. The Al(1,2)-O(10) bond length is 1.82 Å. The Al(1,2)-O(6) bond length is 1.81 Å. The Al(1,2)-O(8) bond length is 1.76 Å. In the second Al site, Al(3,5) is bonded to one O(13), one O(15), and two equivalent O(5) atoms to form AlO4 tetrahedra that share  a cornercorner with one P(3)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Al(3,5)-O(13) bond length is 1.78 Å. The Al(3,5)-O(15) bond length is 1.79 Å. Both Al(3,5)-O(5) bond lengths are 1.79 Å. In the third Al site, Al(4) is bonded to one O(16), one O(18), and two equivalent O(3) atoms to form AlO4 tetrahedra that share  a cornercorner with one P(4)O4 tetrahedra,  a cornercorner with one P(5)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Al(4)-O(16) bond length is 1.90 Å. The Al(4)-O(18) bond length is 2.01 Å. Both Al(4)-O(3) bond lengths are 1.91 Å. There are six inequivalent P sites. In the first 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  a cornercorner with one Al(3,5)O4 tetrahedra;  a cornercorner with one Al(4)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(1)-O(3) bond length is 1.50 Å. The P(1)-O(4) bond length is 1.54 Å. The P(1)-O(5) bond length is 1.50 Å. The P(1)-O(6) bond length is 1.55 Å. In the second P site, P(2) is bonded to one O(10), one O(11), one O(12), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra;  a cornercorner with one Al(3,5)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(2)-O(10) bond length is 1.54 Å. The P(2)-O(11) bond length is 1.50 Å. The P(2)-O(12) bond length is 1.55 Å. The P(2)-O(9) bond length is 1.50 Å. In the third P site, P(3) is bonded to one O(13), one O(14), and two equivalent O(1) atoms to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra;  a cornercorner with one Al(3,5)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(3)-O(13) bond length is 1.53 Å. The P(3)-O(14) bond length is 1.51 Å. Both P(3)-O(1) bond lengths are 1.53 Å. In the fourth P site, P(4) is bonded to one O(15), one O(16), and two equivalent O(2) atoms to form PO4 tetrahedra that share  a cornercorner with one Al(3,5)O4 tetrahedra;  a cornercorner with one Al(4)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(4)-O(15) bond length is 1.49 Å. The P(4)-O(16) bond length is 1.49 Å. Both P(4)-O(2) bond lengths are 1.48 Å. In the fifth P site, P(5) is bonded to one O(17), one O(18), and two equivalent O(7) atoms to form PO4 tetrahedra that share  a cornercorner with one Al(3,5)O4 tetrahedra;  a cornercorner with one Al(4)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(5)-O(17) bond length is 1.53 Å. The P(5)-O(18) bond length is 1.51 Å. Both P(5)-O(7) bond lengths are 1.53 Å. In the sixth P site, P(6) is bonded to one O(19), one O(20), and two equivalent O(8) atoms to form PO4 tetrahedra that share  a cornercorner with one Mg(1)O4 tetrahedra;  a cornercorner with one Al(3,5)O4 tetrahedra; and corners with two equivalent Al(1,2)O4 tetrahedra. The P(6)-O(19) bond length is 1.49 Å. The P(6)-O(20) bond length is 1.49 Å. Both P(6)-O(8) bond lengths are 1.48 Å. There are twenty inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(3) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(4) atom. The O(2)-Al(1,2) bond length is 1.76 Å. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Al(4) and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(1) atom. The O(4)-Al(1,2) bond length is 1.82 Å. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Al(3,5) and one P(1) atom. In the sixth O site, O(6) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(1) atom. In the seventh O site, O(7) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(5) atom. The O(7)-Al(1,2) bond length is 1.77 Å. In the eighth O site, O(8) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(6) atom. In the ninth O site, O(9) is bonded in a distorted bent 150 degrees geometry to one Mg(1) and one P(2) atom. In the tenth O site, O(10) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(2) atom. In the eleventh O site, O(11) is bonded in a bent 150 degrees geometry to one Al(3,5) and one P(2) atom. The O(11)-Al(3,5) bond length is 1.79 Å. In the twelfth O site, O(12) is bonded in a bent 150 degrees geometry to one Al(1,2) and one P(2) atom. The O(12)-Al(1,2) bond length is 1.81 Å. In the thirteenth O site, O(13) is bonded in a bent 120 degrees geometry to one Al(3,5) and one P(3) atom. In the fourteenth O site, O(14) is bonded in a bent 150 degrees geometry to one Mg(1) and one P(3) atom. In the fifteenth O site, O(15) is bonded in a bent 150 degrees geometry to one Al(3,5) and one P(4) atom. In the sixteenth O site, O(16) is bonded in a linear geometry to one Al(4) and one P(4) atom. In the seventeenth O site, O(17) is bonded in a bent 120 degrees geometry to one Al(3,5) and one P(5) atom. The O(17)-Al(3,5) bond length is 1.78 Å. In the eighteenth O site, O(18) is bonded in a bent 150 degrees geometry to one Al(4) and one P(5) atom. In the nineteenth O site, O(19) is bonded in a bent 150 degrees geometry to one Al(3,5) and one P(6) atom. The O(19)-Al(3,5) bond length is 1.79 Å. In the twentieth O site, O(20) is bonded in a linear geometry to one Mg(1) and one P(6) atom. Linkers: 16 [O]P([O])([O])=O. Metal clusters: 2 [Mg] ,14 [Al]. The MOF has largest included sphere 5.23 A, density 1.62 g/cm3, surface area 2771.86 m2/g, accessible volume 0.30 cm3/g