ON THE ACCURACY OF AVERAGED RELATIVISTIC SHAPE-CONSISTENT PSEUDOPOTENTIALS

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 ref erence calculation on the pseudopotential extraction is discussed with in a given type of fitting procedure. New pseudopotentials extracted f rom multiconfigurational 4-component calculations including core polar ization effects are proposed, and they are compared to pseudopotential s extracted from SCF-4-component or scalar relativistic calculations a s well as to pseudopotentials extracted with the energy-adjusted proce dure. We have computed atomic transition energies, ionization potentia ls and electron affinities for the halogen atoms (X = F, Cl, Br, I) as well as molecular ground-state properties for X-2 with the different pseudopotentials. The calculations have been carried out at the CI lev el using basis sets extended up to g-functions. The results show excel lent accuracy obtained with the new proposed pseudopotentials. We disc uss the results focusing on the physical information included in the a tomic reference calculations. (C) 1998 Elsevier Science B.V. All right s reserved.