On the use of the Vⁿ⁻ᵐ approximation in atomic calculations

الأصل · EN

We demonstrate that Vⁿ⁻ᵐ approximation is a good starting point for the configuration interaction calculations for many-electron atoms and ions. N is the total number of electrons in the neutral atom, M is the number of valence electrons. Vⁿ⁻ᵐ is the self-consistent Hartree Fock potential for a closed-shell ion with all valence electrons removed. Using of the Vⁿ⁻ᵐ approximation considerably simplifies the many-body perturbation theory for the core-valence correlations. It makes it easier to include higher-order correlations which often significantly improves the accuracy of the calculations. Calculations for krypton and barium and their positive ions are presented for illustration.