Fig. 2: Band structure of halide double perovskites.

a Band structure of CAIC, CABC, and CASC with a display of dominant orbital characters. The parity of the valence and conduction band edges is shown in Koster notations. b The corresponding molecular orbital pictures as obtained by analyzing the orbital-resolved band structure and density of states (not shown here). In the inset, the nature of the hybridization among the hybridized Ag-eg and In/Bi/Sb-s orbitals is schematically shown to distinguish the shape of the dispersion in valence and conduction band edges in these compounds.