Electronic stopping power from first-principles calculations with account for core electron excitations and projectile ionization

Abstract

We use Ehrenfest dynamics and time-dependent density functional theory to calculate electronic stopping power ${S}_{e}$ of energetic ions in graphitic targets from first principles. By treating core electrons as valence electrons within the projected augmented wave framework, we demonstrate that this approach provides an accurate description of ${S}_{e}$ for a wide range of ions and ion energies, even when not only valence, but also core electron excitations are essential. Our impact-parameter-dependent approach capable of describing the stopping of both low- and high-energy ions is a significant step forward in ${S}_{e}$ calculations, as it makes it possible to monitor projectile charge state during impacts, estimate contributions of core and valence electron excitations to ${S}_{e}$, and it gives a quantitative description of electronic stopping in the cross-over region for bulk solids and nanostructures from first principles.