Effect of pressure on mechanical and optical properties of ThO2 and PuO2

We have used DFT + U with spin-orbit coupling to understand the effect of pressure on the mechanical and optical properties of ThO2 and PuO2. Both the compounds are mechanically stable in a cubic and an orthorhombic structure. The cubic AnO(2) has higher elastic constants and Bader charges on each atom than the orthorhombic AnO(2). With an increase in pressure on cubic AnO(2), elastic modulus increases for both the structures. Bader charge on AnO(2) and magnetic moment of PuO2 decrease with an increase in pressure for cubic structure. The static refractive index and static dielectric function are higher for PuO2 in both the cubic and orthorhombic structures as compared to that in ThO2. The mechanical and optical properties drawn comply with the experimental outcomes.