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. (author)