2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/108558Density Functional Theory's Kohn-Sham (KS) potential emerges as the minimizing effective potential in an unconstrained variational scheme that does not involve fixing the unknown single-electron density. The physical content behind the virtual KS system, that of a non-interacting electronic system representing optimally the interacting one, is brought to light.Other Condensed Mattertext