On the accuracy of averaged relativistic shape-consistent pseudopotentials Original Research Article

The pseudopotentials now available in the literature differ in the way of fitting the pseudopotentials as well as in the atomic relativistic (or not) reference data. The influence of the atomic relativistic reference calculation on the pseudopotential extraction is discussed within a given type of fitting procedure. New pseudopotentials extracted from multiconfigurational 4-component calculations including core polarization effects are proposed, and they are compared to pseudopotentials extracted from SCF-4-component or scalar relativistic calculations as well as to pseudopotentials extracted with the energy-adjusted procedure. We have computed atomic transition energies, ionization potentials and electron affinities for the halogen atoms (X=F, Cl, Br, I) as well as molecular ground-state properties for X2 with the different pseudopotentials. The calculations have been carried out at the CI level using basis sets extended up to g-functions. The results show excellent accuracy obtained with the new proposed pseudopotentials. We discuss the results focusing on the physical information included in the atomic reference calculations.