On the structure of α‐UO₃

From the neutron diffraction pattern of a ‐UO 3 it was found that the generally accepted hexagonal structure is incorrect. Both chemical and structural arguments have led us to regard a ‐UO 3 as an imperfectly crystalline form of the orthorhombic modification generally called UO 2.9. This substance has an unknown structure which is shown to be disordered.