Dynamical Screened Interactions beyond RPA from Ab Initio Self-consistent GW+EDMFT

Accurate first-principles descriptions of correlated quantum materials require a simultaneous treatment of strong electronic correlations and screening effects. In this talk, I will present a fully self-consistent implementation of GW+EDMFT that combines nonlocal correlations treated at the GW level with a non-perturbative description of local correlations within extended dynamical mean-field theory (EDMFT), where the local correlated subspace is mapped onto a self-consistent quantum impurity problem with dynamically screened interactions embedded in an effective medium. Crucially, we demonstrate that self-consistency in both the Green’s function and the screened interaction is essential for describing screening across energy scales, resolving the overscreening inherent in the constrained random phase approximation (cRPA) commonly used to construct effective interactions. Applied to the Mott insulator SrMnO₃, non-perturbative screening beyond RPA suppresses spurious low-energy screening channels and stabilize a Mott-insulating state in quantitative agreement with photoemission experiments, establishing fully self-consistent GW+EDMFT as a predictive ab initio framework for strongly correlated quantum materials.