Nonempirical hybrid functionals for band gaps of inorganic metal-halide perovskites

The first scheme is based on the static screening response of the material and thus yields dielectric-dependent hybrid functionals.

The second scheme defines the hybrid functionals through the enforcement of Koopmans' condition for localized defect states. We also carry out quasiparticle self-consistent GW calculations with vertex corrections to establish state-of-the-art references. For the investigated class of materials, dielectric-dependent functionals and those fulfilling Koopmans' condition yield band gaps of comparable accuracy (∼0.2 eV), but the former only require calculations for the primitive unit cell and are less subject to the specifics of the material.