Our molecular dynamics simulation used a plane-wave cutoff of 350 eV with only the gamma point used for kspace sampling, and without spin-polarisation. The simulation was performed at 600 K and used a time-step of 2 fs. Before our production run, we obtained the 600 K equilibrium volume by running a preliminary series of simulations with different cell volumes for 8 ps each, and fitting the Birch-Murnaghan equation to the resulting energy-volume dataset. The simulation was run in the N V T ensemble using a Nosé-Hoover thermostat. Thermal equilibration was performed by running a 2 ps N V E run with temperature rescaling every 50 steps. The production run was 159 ps in length.