Comment on ‘The spectral decomposition of the helium atom two-electron configuration in terms of hydrogenic orbitals’

Abstract

Brief remarks are made concerning Hutchinson et al 's paper (2013 Eur. J. Phys. 34 111) about the ground configuration of the helium atom and the importance of continuum states. The purpose of our comment is twofold: firstly, to indicate that even when using a good basis set, obtained using the self-consistent Hartree–Fock method, the contribution of other bound states and continuum ones is of some importance to calculate energy levels; and secondly, to emphasize that continuum states can be of great importance to satisfy several rigorous sum rules.