Zn2C21PH13O8 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded to one O(4), one O(5), one O(6), and two equivalent O(8) atoms to form a mixture of edge and corner-sharing ZnO5 trigonal bipyramids. The Zn(1)-O(4) bond length is 1.98 Å. The Zn(1)-O(5) bond length is 1.96 Å. The Zn(1)-O(6) bond length is 2.13 Å. There is one shorter (2.00 Å) and one longer (2.13 Å) Zn(1)-O(8) bond length. In the second Zn site, Zn(2) is bonded to one O(1), one O(2), one O(3), one O(7), and one O(8) atom to form ZnO5 trigonal bipyramids that share  a cornercorner with one P(1)C3O tetrahedra and corners with two equivalent Zn(1)O5 trigonal bipyramids. The Zn(2)-O(1) bond length is 2.10 Å. The Zn(2)-O(2) bond length is 1.99 Å. The Zn(2)-O(3) bond length is 1.98 Å. The Zn(2)-O(7) bond length is 2.17 Å. The Zn(2)-O(8) bond length is 2.01 Å. There are twenty-one inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(11), one C(15), and one P(1) atom. The C(1)-C(11) bond length is 1.36 Å. The C(1)-C(15) bond length is 1.37 Å. The C(1)-P(1) bond length is 1.80 Å. In the second C site, C(2) is bonded in a trigonal planar geometry to one C(12), one C(19), and one P(1) atom. The C(2)-C(12) bond length is 1.39 Å. The C(2)-C(19) bond length is 1.39 Å. The C(2)-P(1) bond length is 1.79 Å. In the third C site, C(3) is bonded in a distorted trigonal planar geometry to one C(14), one C(9), and one P(1) atom. The C(3)-C(14) bond length is 1.38 Å. The C(3)-C(9) bond length is 1.38 Å. The C(3)-P(1) bond length is 1.80 Å. In the fourth C site, C(4) is bonded in a trigonal planar geometry to one C(5), one C(6), and one C(7) atom. The C(4)-C(5) bond length is 1.50 Å. The C(4)-C(6) bond length is 1.40 Å. The C(4)-C(7) bond length is 1.38 Å. In the fifth C site, C(5) is bonded in a distorted bent 120 degrees geometry to one C(4), one O(2), and one O(5) atom. The C(5)-O(2) bond length is 1.25 Å. The C(5)-O(5) bond length is 1.26 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(4) and one H(1) atom. The C(6)-H(1) bond length is 0.93 Å. In the seventh C site, C(7) is bonded in a distorted trigonal planar geometry to one C(14), one C(4), and one H(2) atom. The C(7)-C(14) bond length is 1.38 Å. The C(7)-H(2) bond length is 0.93 Å. In the eighth C site, C(8) is bonded in a trigonal planar geometry to one C(10), one C(13), and one C(18) atom. The C(8)-C(10) bond length is 1.52 Å. The C(8)-C(13) bond length is 1.39 Å. The C(8)-C(18) bond length is 1.36 Å. In the ninth C site, C(9) is bonded in a distorted single-bond geometry to one C(3) and one H(4) atom. The C(9)-H(4) bond length is 0.93 Å. In the tenth C site, C(10) is bonded in a distorted bent 120 degrees geometry to one C(8), one O(3), and one O(6) atom. The C(10)-O(3) bond length is 1.26 Å. The C(10)-O(6) bond length is 1.24 Å. In the eleventh C site, C(11) is bonded in a distorted single-bond geometry to one C(1) and one H(5) atom. The C(11)-H(5) bond length is 0.93 Å. In the twelfth C site, C(12) is bonded in a distorted single-bond geometry to one C(2) and one H(6) atom. The C(12)-H(6) bond length is 0.93 Å. In the thirteenth C site, C(13) is bonded in a distorted single-bond geometry to one C(8) and one H(7) atom. The C(13)-H(7) bond length is 0.93 Å. In the fourteenth C site, C(14) is bonded in a distorted single-bond geometry to one C(3), one C(7), and one H(8) atom. The C(14)-H(8) bond length is 0.93 Å. In the fifteenth C site, C(15) is bonded in a distorted single-bond geometry to one C(1), one C(17), and one H(9) atom. The C(15)-C(17) bond length is 1.39 Å. The C(15)-H(9) bond length is 0.93 Å. In the sixteenth C site, C(16) is bonded in a distorted single-bond geometry to one C(20) and one H(10) atom. The C(16)-C(20) bond length is 1.37 Å. The C(16)-H(10) bond length is 0.93 Å. In the seventeenth C site, C(17) is bonded in a distorted trigonal planar geometry to one C(15), one C(20), and one H(11) atom. The C(17)-C(20) bond length is 1.37 Å. The C(17)-H(11) bond length is 0.93 Å. In the eighteenth C site, C(18) is bonded in a distorted trigonal planar geometry to one C(19), one C(8), and one H(12) atom. The C(18)-C(19) bond length is 1.39 Å. The C(18)-H(12) bond length is 0.93 Å. In the nineteenth C site, C(19) is bonded in a distorted trigonal planar geometry to one C(18), one C(2), and one H(13) atom. The C(19)-H(13) bond length is 0.93 Å. In the twentieth C site, C(20) is bonded in a trigonal planar geometry to one C(16), one C(17), and one C(21) atom. The C(20)-C(21) bond length is 1.51 Å. In the twenty-first C site, C(21) is bonded in a bent 120 degrees geometry to one C(20), one O(4), and one O(7) atom. The C(21)-O(4) bond length is 1.25 Å. The C(21)-O(7) bond length is 1.24 Å. P(1) is bonded to one C(1), one C(2), one C(3), and one O(1) atom to form PC3O tetrahedra that share  a cornercorner with one Zn(2)O5 trigonal bipyramid. The P(1)-O(1) bond length is 1.49 Å. There are thirteen inequivalent H sites. In the first H site, H(1) is bonded in a single-bond geometry to one C(6) atom. In the second H site, H(2) is bonded in a single-bond geometry to one C(7) atom. In the third H site, H(3) is bonded in a single-bond geometry to one O(8) atom. The H(3)-O(8) bond length is 0.85 Å. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(9) atom. In the fifth H site, H(5) is bonded in a single-bond geometry to one C(11) atom. In the sixth H site, H(6) is bonded in a single-bond geometry to one C(12) atom. In the seventh H site, H(7) is bonded in a single-bond geometry to one C(13) atom. In the eighth H site, H(8) is bonded in a single-bond geometry to one C(14) atom. In the ninth H site, H(9) is bonded in a single-bond geometry to one C(15) atom. In the tenth H site, H(10) is bonded in a single-bond geometry to one C(16) atom. In the eleventh H site, H(11) is bonded in a single-bond geometry to one C(17) atom. In the twelfth H site, H(12) is bonded in a single-bond geometry to one C(18) atom. In the thirteenth H site, H(13) is bonded in a single-bond geometry to one C(19) atom. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a bent 150 degrees geometry to one Zn(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one Zn(2) and one C(5) atom. In the third O site, O(3) is bonded in a bent 120 degrees geometry to one Zn(2) and one C(10) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(21) atom. In the fifth O site, O(5) is bonded in a bent 150 degrees geometry to one Zn(1) and one C(5) atom. In the sixth O site, O(6) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(10) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Zn(2) and one C(21) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to one Zn(2), two equivalent Zn(1), and one H(3) atom. Linkers: 4 [O]C(=O)c1ccc(P(=O)(c2ccc(C([O])=O)cc2)c2ccc(C([O])=O)cc2)cc1. Metal clusters: 2 [O][Zn@]12O[C]O[Zn@](O)(O[C]O1)O[C]O[Zn@]1([O])O[C]O[Zn@@](O)(O[C]O1)O[C]O2. RCSR code: flu. The MOF has largest included sphere 9.13 A, density 0.96 g/cm3, surface area 3918.03 m2/g, accessible volume 0.55 cm3/g