K4Pt2P8O20I crystallizes in the orthorhombic Cmmm space group. K(1) is bonded in a 5-coordinate geometry to one K(1), two equivalent O(1), and two equivalent O(2) atoms. The K(1)-K(1) bond length is 0.55 Å. Both K(1)-O(1) bond lengths are 2.71 Å. Both K(1)-O(2) bond lengths are 3.08 Å. Pt(1) is bonded to one Pt(1), four equivalent P(1), and one I(1) atom to form distorted corner-sharing PtP4PtI octahedra. The corner-sharing octahedra are not tilted. The Pt(1)-Pt(1) bond length is 2.80 Å. All Pt(1)-P(1) bond lengths are 2.33 Å. The Pt(1)-I(1) bond length is 2.84 Å. P(1) is bonded in a distorted trigonal non-coplanar geometry to one Pt(1), one O(1), one O(2), and one O(3) atom. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.54 Å. The P(1)-O(3) bond length is 1.59 Å. There are three inequivalent O sites. In the first O site, O(3) is bonded in a distorted bent 120 degrees geometry to two equivalent P(1) atoms. In the second O site, O(1) is bonded in a distorted single-bond geometry to one K(1) and one P(1) atom. In the third O site, O(2) is bonded in a single-bond geometry to one K(1) and one P(1) atom. I(1) is bonded in a linear geometry to two equivalent Pt(1) atoms. Linkers: 8 O=P(=O)OP(=O)=O. Metal clusters: 4 [K][K].[O][P][O].[O][P][O].[O][P][O].[O][P][O]. The MOF has largest included sphere 4.90 A, density 2.83 g/cm3, surface area 1481.06 m2/g, accessible volume 0.11 cm3/g