Å to above 3.0 Å, see Figure . Similarly, the hole Kohn-Sham orbital localized within strongly shortened axial Ag-Cl bonds of 2.3 Å, see Figure . The calculated emission signal is of 1.46 eV while the estimated absorption is at 2.8 eV, see Table . Note that halide vacancies likely strongly contribute to the emission. Self-trapping of excitons is key to observe broad emission features, while the detailed contribution of STEs or by recombination from halide vacancies is still under debate. Interface Model