LDA+U Study on Plutonium Dioxide with Spin-Orbit Couplings

We perform first-principles density functional calculations on plutonium dioxides considering proper relativistic effects and strong correlations with the LDA+ U method. Though this material is a paramagnetic insulator, standard local density approximation (LDA) predicts metallic states. In this paper, we point out that not only strong correlations but also spin-orbit couplings as relativistic effects are necessary to obtain paramagnetic insulating states. Based on this proper method, we also calculate physical properties of plutonium dioxide and compare them with experiments.