All aforementioned calculations besides the TD-lc-DFTB ones were done using Gaussian 16. The TD-lc-DFTB calculations were done using DFTBaby (release January 11, 2021). We also performed cluster (molecular) and periodic BSE@G 0 W 0 @DFT calculations. The cluster BSE@G 0 W 0 @DFT calculations were done with the FHI-aims package. First a standard self-consistent DFT calculation with the PBE functional was performed with a numeric atom-centered tier 2 basis to give the Kohn-Sham eigenvalues and the corresponding orbitals. A perturbative one shot G 0 W 0 calculation 36 was then applied on top of the PBE reference, to get the self energy and the corresponding quasiparticle energies. A two pole fitting for the analytical continuation was applied with a 200 grid point Gauss-Legendre grid for the numerical integration of the integral over the imaginary frequency axis. The Tamm-Dancoff approximation (TDA) was applied to decrease computational cost.