  This work assess the reliability of the recently proposed [Phys. Rev. Lett.
127, 233001, 2021] global natural orbital functional (GNOF) in the treatment of
the strong electron correlation regime. We first use an H10 benchmark set of
four hydrogen model systems of different dimensionalities and distinctive
electronic structures: a 1D chain, a 2D ring, a 2D sheet, and a 3D close-packed
pyramid. Second, we study two paradigmatic models for strongly correlated Mott
insulators, namely a 1D H50 chain and a 4x4x4 3D H cube. We show that GNOF
without hybridization to other electronic structure methods and free of tuned
parameters succeeds in treating weak and strong correlation in a more balanced
way than the functionals that have preceded it.
