KZnC8PH4O7 crystallizes in the monoclinic P2_1/c space group. K(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(5), one O(6), and two equivalent O(3) atoms. The K(1)-O(1) bond length is 2.80 Å. The K(1)-O(2) bond length is 2.85 Å. The K(1)-O(5) bond length is 2.61 Å. The K(1)-O(6) bond length is 2.86 Å. There is one shorter (2.76 Å) and one longer (2.85 Å) K(1)-O(3) bond length. Zn(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form ZnO4 tetrahedra that share corners with three equivalent P(1)CO3 tetrahedra. The Zn(1)-O(1) bond length is 1.96 Å. The Zn(1)-O(2) bond length is 1.95 Å. The Zn(1)-O(3) bond length is 2.00 Å. The Zn(1)-O(7) bond length is 1.95 Å. There are eight inequivalent C sites. In the first C site, C(1) is bonded in a trigonal planar geometry to one C(2), one C(6), and one P(1) atom. The C(1)-C(2) bond length is 1.40 Å. The C(1)-C(6) bond length is 1.40 Å. The C(1)-P(1) bond length is 1.81 Å. In the second C site, C(2) is bonded in a distorted single-bond geometry to one C(1), one C(3), and one H(2) atom. The C(2)-C(3) bond length is 1.40 Å. The C(2)-H(2) bond length is 1.09 Å. In the third C site, C(3) is bonded in a trigonal planar geometry to one C(2), one C(4), and one C(7) atom. The C(3)-C(4) bond length is 1.40 Å. The C(3)-C(7) bond length is 1.49 Å. In the fourth C site, C(4) is bonded in a distorted single-bond geometry to one C(3), one C(5), and one H(3) atom. The C(4)-C(5) bond length is 1.40 Å. The C(4)-H(3) bond length is 1.09 Å. In the fifth C site, C(5) is bonded in a trigonal planar geometry to one C(4), one C(6), and one C(8) atom. The C(5)-C(6) bond length is 1.40 Å. The C(5)-C(8) bond length is 1.50 Å. In the sixth C site, C(6) is bonded in a distorted single-bond geometry to one C(1), one C(5), and one H(4) atom. The C(6)-H(4) bond length is 1.09 Å. In the seventh C site, C(7) is bonded in a distorted bent 120 degrees geometry to one C(3), one O(4), and one O(5) atom. The C(7)-O(4) bond length is 1.33 Å. The C(7)-O(5) bond length is 1.24 Å. In the eighth C site, C(8) is bonded in a distorted bent 120 degrees geometry to one C(5), one O(6), and one O(7) atom. The C(8)-O(6) bond length is 1.26 Å. The C(8)-O(7) bond length is 1.29 Å. P(1) is bonded to one C(1), one O(1), one O(2), and one O(3) atom to form PCO3 tetrahedra that share corners with three equivalent Zn(1)O4 tetrahedra. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.55 Å. There are four inequivalent H sites. In the first H site, H(1) is bonded in a linear geometry to one O(4) and one O(6) atom. The H(1)-O(4) bond length is 1.03 Å. The H(1)-O(6) bond length is 1.58 Å. In the second H site, H(2) is bonded in a single-bond geometry to one C(2) atom. In the third H site, H(3) is bonded in a single-bond geometry to one C(4) atom. In the fourth H site, H(4) is bonded in a single-bond geometry to one C(6) atom. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one K(1), one Zn(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 120 degrees geometry to one K(1), one Zn(1), and one P(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one Zn(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a water-like geometry to one C(7) and one H(1) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one K(1) and one C(7) atom. In the sixth O site, O(6) is bonded in a 3-coordinate geometry to one K(1), one C(8), and one H(1) atom. In the seventh O site, O(7) is bonded in a bent 120 degrees geometry to one Zn(1) and one C(8) atom. Linkers: 4 [O]C(=O)c1cc(C(=O)O)cc(P([O])[O])c1 ,4 [O]C(=O)c1cc(C(=O)O)cc(P([O])([O])=O)c1 ,4 [O]P([O])(=O)c1c[c]cc(C(=O)O)c1. Metal clusters: 4 [K] ,4 [Zn]. The MOF has largest included sphere 1.98 A, density 2.01 g/cm3, surface area 2372.44 m2/g, accessible volume 0.07 cm3/g