2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/164964In their recent work Cooper and Ponec [Phys. Chem. Chem. Phys., 2008, 10, 1319-1329] proposed a ``one-electron approximation to domain-averaged Fermi hole (DAFH)" used in electronic population studies. The goal of this comment is to note that the proposal had been already published within the framework of domain-restricted reduced density matrices ($\mathrmΩ$-RDM) and to show that it cannot conceptually be considered as an approximation to DAFH as the authors invoke.four pages, no figuresQuantum Physicstext