The Quantum ESPRESSO package 123 was used to compute the DFT eigenvectors and eigenvalues, which served as the starting point for non-self-consistent GW +BSE calculations, using the PBE functional. Norm-conserving pseudopotentials were chosen in order to take advantage of the simplification of matrix elements in GW +BSE calculations. Troullier-Martins norm-conserving pseudopotentials were generated using FHI98PP-converted with fhi2upf.x v.5.0.2 from Abinit Project. The