Calculated equilibrium properties, electronic structures and structural stabilities of Th, Pa, U, Np and Pu

With the FPLAPW (full potential linearized augmented plane wave) method we calculate the equilibrium volumes, the bulk moduli and the electronic structures of the light actinide metals in their crystal structure of ambient conditions. We examine also their structural stability under pressure and we show several phase transitions for Np and Pu. The results are significantly different from the previous calculations. With our fully relativistic MTO (muffin tin orbital) method we find for the stabilized δ-phase (face centred cubic) of Pu an electronic structure which presents a 5f peak pinned at the Fermi level, in agreement with photoelectron spectroscopy and the high value of the electronic specific heat coefficient.