A schematic of the computational workflow is shown in Figure . We use first-principles density functional theory (DFT) to perform structural relaxations, and to calculate electronic band structures and bulk moduli. All DFT calculations are performed with the Vienna Ab Initio Simulation Package (VASP) and the projector augmented wave (PAW) potentials are used to describe the core electrons. The wavefunctions are expanded as plane waves with an energy cuto↵ of 340 eV.