Symmetry-Based Tight Binding Modeling of Halide Perovskite Semiconductors

National audienceEmpirical and semi-empirical models are particularly suited to address issues related to complex structures. Based on a general symmetry analysis, herein we build an empirical sp 3 tight-binding (TB) model for the reference Pm3m cubic phase of halide perovskite structures of general formula ABX 3. This TB model includes 16 and 32 basis functions without and with spin orbit coupling (SOC), respectively . The 16 basis functions are made of one " s " and three " p " orbitals for the metal atom B, and the same for three halide atoms X atoms