Many-Body and Single-Body Low-Energy Elastic Positron Scattering by Beryllium Atoms: From Ab Initio to Semiempirical Approaches

Optical and energy-loss spectra of MgO, ZnO, and CdO from ab initio many-body calculations

We compute optical properties including excitonic effects for the equilibrium polymorphs of three group-II metal monoxides by solving the Bethe-Salpeter equation. The underlying electronic structures are based on results of a recently developed GW approach starting from a hybrid exchange-correlation functional. The resulting quasiparticle band structures are discussed with respect to their mapp...

Ab Initio Many-Body Calculations of Deuteron-4He Scattering And 6Li States

Ab initio GW many-body effects in graphene.

We present an ab initio numerical many-body GW calculation of the band plot in freestanding graphene. We consider the full ionic and electronic structure introducing e-e interaction and correlation effects via a self-energy containing non-Hermitian and dynamical terms. With respect to the density-functional theory local-density approximation, the Fermi velocity is renormalized with an increase ...

Low-energy positron scattering from atoms and molecules using positron accumulation techniques

Positron scattering from atoms and molecules is studied at low values of incident positron energy. The experiments use a cold magnetized positron beam formed in a positron accumulator. A discussion of positron scattering in a magnetic ®eld is presented along with di€erential cross-sections (DCS) for positron±atom collisions and positron± molecule total vibrational excitation cross-sections. Abs...

Many-body wave scattering by small bodies

Acoustic or electromagnetic EM wave scattering by one or several bodies is usually studied by reducing the problem to solving some integral equations. In this paper we show that if the bodies are small in comparison with the wavelength, then the scattering problem can be reduced to solving linear algebraic systems with matrices whose elements have physical meaning. These elements are electrical...