New Model Potential for Pseudopotential Calculations

The use of model potentials in pseudopotential calculations is discussed, and a set of desirable criteria for model potentials is suggested. The Hellmann potential and the Abarenkov and Heine potential are examined, and it is shown that both potentials are useful, but neither fully satisfies the suggested desiderata. A new potential of the form, V(r) = − Z / r + ΣlBlPl / r2, where Pl is the projection operator over the subspace of spherical harmonics of a given l, is proposed. A physical interpretation of the potential in terms of a “Pauli force” and a polarized core is given. Ionization energies for excited S, P, D, and F states for one-valence-electron atoms are calculated. The new potential is also applied to two-valence-electron atoms, and their calculated valence-state energies are shown to be in good agreement with experimental values.