The Pauli energy grows exponentially with the electronic localisation

Abstract

We investigate the Pauli energy in atoms and molecules as a measure of electron localisation. Our results indicate that the Pauli energy has an exponential dependence on the number of localised electrons. This relationship yields to a kinetic energy density expression that depends on the electron density ρ(r) and the pair density ρ2(r, r′). The proposed equation shows certain advantages over a similar orbital-free kinetic energy functional recently proposed by Delle Site and co-workers. The methodology introduced here is a novel approach for exploring electronic quantities with a partition scheme that might be useful for research in density functional theory.