Benchmarking GNOF against FCI in challenging systems in one, two and three dimensions

Abstract

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 use a 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. 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.