Ab-initio calculation on electronic and optical properties of ThO2, UO2 and PuO2

We have investigated the structural and electronic properties of oxides of Th, U and Pu using GGA + U method. Structure of these oxides is of cubic nature and they have indirect band gaps of 4.34 eV along M→R (ThO2), 2.30 eV along Γ→R (UO2) and 2.27 eV along M→R (PuO2). The density of states (DOS) of these oxides shows main contribution of 2p orbital in valence band maxima (VBM) of ThO2 and PuO2 while in UO2 5f orbital contributes mainly in VBM. We also investigated the optical properties of these oxides and found that static dielectric function increases from ThO2 to PuO2.