Pentapotassium trihydrogenhexatungstoplatinate(IV) hexahydrate, K5[H3PtW6O24]·6H2O

The [H3PtW6O24]5− anion has close to \overline 3m symmetry, with Pt—O bond lengths in the range 1.97 (1)–2.01 (1) Å and W—O bond lengths in the ranges 1.72 (1)–1.78 (1) (Ot), 1.91 (1)–1.96 (1) (Ob) and 2.14 (1)–2.33 (1) Å (Oc), where Ot are terminal atoms, Ob bridge two W atoms, and Oc triply bridge one Pt and two W atoms. The protonated O atoms participate in strong interanion hydrogen bonds.