Solid-State Structures of XeO3

The solid-state structure of xenon trioxide, XeO₃, was reinvestigated by low-temperature single-crystal X-ray diffraction and shown to exhibit polymorphism that is dependent on the crystallization conditions. The previously reported α-phase (orthorhombic, P2₁2₁2₁) only forms upon evaporation of aqueous HF solutions of XeO₃. In contrast, two new phases, β-XeO₃ (rhombohedral, R3) and γ-XeO₃ (rhombohedral, R3c), have been obtained by slow …