Modelling the High Temperature Magnetic Order of Plutonium Dioxide

In order to make accurate predictions for high-temperature conditions in the plutonia (PuO₂) system, paramagnetic ordering of the system has been simulated successfully using a combination of molecular dyamics and density functional theory (DFT). Unlike previous calculations, where the 0 K ground state properties are predicted, here we assess the room temperature magnetic order of the system. A range of methods have been used to enable this assessment involving noncollinear magnetism and the use of spin-orbit coupling within the density functional theory framework. This work has led to the formation of a robust model of room temperature (300K) plutonium dioxide, using a method which could potentially facilitate modelling of paramagnetism in other similar materials.