Pressure-induced formation of KrO₂ from first-principles study

By first-principles study, we propose a hypothetical crystal (with space group P42/MNM) Krypton dioxide (KrO 2 ) which might be synthesized at a pressure over 95[Formula: see text]GPa. At a pressure around 95[Formula: see text]GPa noticeable charge transfer from Kr atom to O atom occurs and chemical bonds are formed. Mechanism of this phenomena is analyzed using the electron-hopping mechanism. The formed Kr–O bond at high pressure can exist with retreated pressure down to 5[Formula: see text]GPa. The electron hopping mechanism might be applicable to the fabrication of other noble gas compounds.