for : “ Calcium peroxide from ambient to high pressures ”

In our searches, we use a lower plane-wave basis cutoff of 500 eV and a coarser k-point sampling density of 2π×0.07 Å−1 along with ultrasoft pseudopotentials generated by the castep code. Once low-enthalpy candidate structures have been identified, we proceed with the higher basis cutoff energy of 800 eV and k-point sampling density of 2π×0.03 Å−1. All results presented in the main paper use this stricter set of parameters, with the exception of the oxygen structures, where a denser k-point sampling is needed owing to the metallic nature of some of its phases.