Comparison of the utility of the shape function and electron density for predicting periodic properties: Atomic ionization potentials

Using data from atomic Hartree-Fock calculations, we examine whether it is easier to predict the ionization potential of a system using its shape function or using its electron density. A simple linear combination of two moments of the shape function capably predicts the periodic trends in the ionization potential, while a similar expansion in terms of the electron density does not. While it is known that the shape function determines all the …