U5(PO4)4 crystallizes in the monoclinic Pc space group. There are five inequivalent U sites. In the first U site, U(1) is bonded in a distorted pentagonal planar geometry to one O(1), one O(12), one O(14), one O(2), and one O(9) atom. The U(1)-O(1) bond length is 2.38 Å. The U(1)-O(12) bond length is 2.47 Å. The U(1)-O(14) bond length is 2.39 Å. The U(1)-O(2) bond length is 2.51 Å. The U(1)-O(9) bond length is 2.32 Å. In the second U site, U(2) is bonded in a distorted pentagonal planar geometry to one O(1), one O(10), one O(12), one O(14), and one O(2) atom. The U(2)-O(1) bond length is 2.49 Å. The U(2)-O(10) bond length is 2.31 Å. The U(2)-O(12) bond length is 2.35 Å. The U(2)-O(14) bond length is 2.50 Å. The U(2)-O(2) bond length is 2.35 Å. In the third U site, U(3) is bonded in a distorted pentagonal planar geometry to one O(3), one O(4), one O(5), one O(7), and one O(8) atom. The U(3)-O(3) bond length is 2.52 Å. The U(3)-O(4) bond length is 2.37 Å. The U(3)-O(5) bond length is 2.39 Å. The U(3)-O(7) bond length is 2.29 Å. The U(3)-O(8) bond length is 2.48 Å. In the fourth U site, U(4) is bonded in a distorted pentagonal planar geometry to one O(3), one O(4), one O(5), one O(6), and one O(8) atom. The U(4)-O(3) bond length is 2.34 Å. The U(4)-O(4) bond length is 2.51 Å. The U(4)-O(5) bond length is 2.50 Å. The U(4)-O(6) bond length is 2.30 Å. The U(4)-O(8) bond length is 2.35 Å. In the fifth U site, U(5) is bonded in a 4-coordinate geometry to one O(11), one O(13), one O(15), and one O(16) atom. The U(5)-O(11) bond length is 2.35 Å. The U(5)-O(13) bond length is 2.33 Å. The U(5)-O(15) bond length is 2.39 Å. The U(5)-O(16) bond length is 2.39 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded in a tetrahedral geometry to one O(15), one O(4), one O(5), and one O(6) atom. The P(1)-O(15) bond length is 1.49 Å. The P(1)-O(4) bond length is 1.57 Å. The P(1)-O(5) bond length is 1.56 Å. The P(1)-O(6) bond length is 1.52 Å. In the second P site, P(2) is bonded in a tetrahedral geometry to one O(11), one O(3), one O(7), and one O(8) atom. The P(2)-O(11) bond length is 1.49 Å. The P(2)-O(3) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.56 Å. The P(2)-O(8) bond length is 1.56 Å. In the third P site, P(3) is bonded in a tetrahedral geometry to one O(1), one O(10), one O(14), and one O(16) atom. The P(3)-O(1) bond length is 1.56 Å. The P(3)-O(10) bond length is 1.50 Å. The P(3)-O(14) bond length is 1.55 Å. The P(3)-O(16) bond length is 1.48 Å. In the fourth P site, P(4) is bonded in a tetrahedral geometry to one O(12), one O(13), one O(2), and one O(9) atom. The P(4)-O(12) bond length is 1.56 Å. The P(4)-O(13) bond length is 1.49 Å. The P(4)-O(2) bond length is 1.55 Å. The P(4)-O(9) bond length is 1.55 Å. There are sixteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one U(1), one U(2), and one P(3) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one U(1), one U(2), and one P(4) atom. In the third O site, O(3) is bonded in a distorted single-bond geometry to one U(3), one U(4), and one P(2) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to one U(3), one U(4), and one P(1) atom. In the fifth O site, O(5) is bonded in a distorted single-bond geometry to one U(3), one U(4), and one P(1) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to one U(4) and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted single-bond geometry to one U(3) and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one U(3), one U(4), and one P(2) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to one U(1) and one P(4) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to one U(2) and one P(3) atom. In the eleventh O site, O(11) is bonded in a distorted single-bond geometry to one U(5) and one P(2) atom. In the twelfth O site, O(12) is bonded in a distorted single-bond geometry to one U(1), one U(2), and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted single-bond geometry to one U(5) and one P(4) atom. In the fourteenth O site, O(14) is bonded in a distorted single-bond geometry to one U(1), one U(2), and one P(3) atom. In the fifteenth O site, O(15) is bonded in a distorted single-bond geometry to one U(5) and one P(1) atom. In the sixteenth O site, O(16) is bonded in a distorted single-bond geometry to one U(5) and one P(3) atom. Linkers: 8 [O]P([O])([O])=O. Metal clusters: 10 [U]. The MOF has largest included sphere 5.80 A, density 3.73 g/cm3, surface area 1118.33 m2/g, accessible volume 0.16 cm3/g