Electronic structure calculations and optical properties of a new organic-inorganic luminescent perovskite: (C9H19NH3)2PbI2Br2

► (C9H19NH3)2PbI2Br2 compound is a new crystal with strong yellow-green PL emission at 2.17 eV. ► Calculations based on DFT and FLAPW method combined with LDA approximation are performed. ► Gap, optical transitions and exciton presence were predicted from density of states. ► Agreement between experimental data and electronic structure calculations.