The experimental absorption spectrum of 3T-a, as reported in Ref. For 3T-b (Fig. ), as ε B becomes more positive, the dark state shifts to the red, while the bright states shift to the blue. Unlike 3T-a, for ε B ≥ 9 eV, the first bright E ′ state is positioned above the A ′ 2 dark state. Within the range of ε B from 10 eV to 12 eV (highlighted ). However, it is important to acknowledge that widely used all-electron approaches come with inherent approximations.