Polarons free from many-body self-interaction in density functional theory

Semilocal density functional theory generally fails in stabilizing polarons, because of its spurious inclusion of the electron self-interaction. This work addresses the concepts of many-body and one-body self-interaction, which are found to be connected through the dielectric constant within a unified theoretical formulation. The superiority of the many-body self-interaction is demonstrated, resulting in robust polaron formation energies. In this context, an efficient semilocal scheme for polaron localization is developed.