Combination of the Perturbation Theory with Configuration Interaction Method

TL;DR

This paper proposes a modified CI+MBPT method to improve atomic calculations for atoms with more than four or five valence electrons, especially those with filled d and f shells, extending reliable predictions to larger atoms.

Contribution

It introduces a new modification of the CI+MBPT method tailored for atoms with complex electron configurations, addressing limitations of existing approaches.

Findings

Enhanced accuracy for atoms with filled d and f shells

Applicable to atoms with more than four valence electrons

Potential for broader atomic predictions

Abstract

Present atomic theory provides accurate and reliable results for atoms with a small number of valence electrons. However, most current methods of calculations fail when the number of valence electrons exceeds four or five. This means that we can not make reliable predictions for more than a half of the periodic table. Here we suggest a modification of the CI+MBPT (configuration interaction plus many-body perturbation theory) method, which may be applicable to atoms and ions with filling d and f shells.