The workflow begins with a structural relaxation using tight convergence criteria to eliminate the presence of imaginary phonon modes (Fig. ). A large supercell (> 15 Å) is constructed to provide sufficient convergence of the renormalised properties. Next, the phonon frequencies and eigenvectors are obtained using DFPT. Subsequently, the ZG special displacement approach is employed to construct displaced supercells that yield accurate thermal averages of the mean squared atomic displacements. We note, an alternative approach is to employ Monte-Carlo sampling of displacements, 99 however the ZG method enables convergence of properties in a one-shot approach. The displaced supercells are constructed using the implementation available in VASP, with one supercell generated for each temperature of interest. For each structure, a uniform band structure calculation is conducted, comprising a static calculation followed by a uniform non-self-consistent field (NSCF) calculation. Meanwhile, a corresponding band structure calculation is performed on the equilibrium supercell to serve as a reference for calculating the renormalized band gap. Finally, the renormalized band gap at each temperate is obtained by comparing the band gap of the equilibrium structure with the averaged band gap calculated from the temperaturedependent displaced structures.