Foundations of optimal tuning in solids via localized orbitals

Electronic structure theory dictates that addition or removal of an electron in solids may be performed equivalently in a single periodic cell or over multiple replicas of cells. This principle leads to concepts of localized orbital, notably Wannier orbitals. It also forms the foundation of optimal tuning strategies in solids. Here, we discuss a framework for understanding and analyzing optimal tuning in solids from the perspective of density functional theory.