On the hyperfine structure of the triplet $n^{3}S-$states of the four-electron atoms and ions

TL;DR

This paper investigates the hyperfine structure of triplet $n^3S$ states in four-electron atoms and ions, emphasizing the importance of triplet electron density at the nucleus and proposing a method to determine it.

Contribution

The authors develop a new procedure to calculate the triplet electron density at the nucleus for four-electron atoms and ions, aiding hyperfine structure analysis.

Findings

Established the necessity of knowing $ ho_T(0)$ for hyperfine splitting.

Developed a method to determine $ ho_T(0)$ for various four-electron systems.

Enhanced understanding of hyperfine interactions in Be-like atoms and ions.

Abstract

Hyperfine structures of the triplet $n^3S-$states in the four-electron Be-atom(s) and Be-like ions are considered. It is shown that to determine the hyperfine structure splitting in such atomic systems one needs to know the triplet electron density at the central atomic nucleus $\rho_T(0)$. We have developed the procedure which allows allows one to determine such an electron density $\rho_T(0)$ for arbitrary four-electron atoms and ions.