Caesium sulfate or cesium sulfate is the inorganic compound and salt with the formula Cs2SO4. It is a white water-soluble solid that is used to prepare dense aqueous solutions for use in isopycnic (or "density-gradient") centrifugation. It is isostructural with potassium salt. * Coordination sphere of one of two types of Cs+ site in Cs2SO4. * Environment of sulfate anion in β-Cs2SO4.