# Theoretical study of electron structure of superheavy elements with an open $6d$-shell, Sg, Bh, Hs and Mt

## TL;DR

This paper presents ab initio calculations of the spectra and properties of superheavy elements Sg, Bh, Hs, and Mt, highlighting relativistic effects and spin-orbit interactions that differ from lighter analogs.

## Contribution

It introduces efficient configuration interaction methods to accurately compute spectra and properties of superheavy elements with open 6d shells, revealing significant relativistic effects.

## Key findings

- Large spin-orbit interactions dominate subshell structures.
- Relativistic effects cause deviations from Hund's rule.
- Calculated properties include energy levels, ionization potentials, and transition amplitudes.

## Abstract

We use recently developed efficient versions of the configuration interaction method to perform {\em ab initio} calculations of the spectra of superheavy elements seaborgium (Sg, $Z=106$), bohrium (Bh, $Z=107$), hassium (Hs, $Z=108$) and meitnerium (Mt, $Z=109$). We calculate energy levels, ionization potentials, isotope shifts and electric dipole transition amplitudes. Comparison with lighter analogs reveals significant differences caused by strong relativistic effects in superheavy elements. Very large spin-orbit interaction distinguishes subshells containing orbitals with a definite total electron angular momentum $j$. This effect replaces Hund's rule holding for lighter elements.