Ab initio phase diagram of thorium

We discuss density functional theory (DFT) calculations of the phase diagram of thorium up to 300 GPa and melt. Calculations are performed for the fcc, bcc, and bct phases of thorium, including static lattice energies, phonons, and melt curve calculations using the Z method. The bcc phase, which is dynamically unstable at low temperature, is studied using DFT-based molecular dynamics in conjunction with the temperature dependent effective potential (TDEP) method. Our results provide a prediction of the topology of the phase diagram for thorium and will enable development of a multiphase equation of state.