Model self-energies for dynamical correlations in transition-metal monoxides

Dynamical correlations beyond static mean-field are of fundamental importance in describing the electronic structure of complex materials like transition-metal oxides, where the low-energy physics is dominated by the interactions between partially filled, very localized d or f shell orbitals. To understand the interplay between screening and localization, high-level and computationally expensive theories such as DFT+DMFT or GW+EMDFT are often required. Given the complexity of these methods, actual calculations require expensive numerical implementations that may also hinder the interpretation of the underlying physics or limit the number of orbitals that can be treated as correlated. Motivated by the success of a recent approach to study local correlations in metals via a simple dynamical self-energy, in this work we propose its generalization to spin-polarized cases, and apply this framework to the study of the antiferromagnetic insulating phases of transition-metal monoxides MnO, FeO, CoO and NiO, considered as prototypical materials for beyond-DFT approaches.