Theoretical energy levels of $1sns$ and $1snp$ states of helium-like ions

TL;DR

This paper calculates the energy levels of specific excited states in helium-like ions from carbon to uranium using advanced relativistic methods, including QED effects, providing detailed uncertainty estimates.

Contribution

It introduces comprehensive relativistic calculations of helium-like ion energy levels across a wide range of elements, incorporating nuclear recoil, QED, and Breit interaction effects.

Findings

Energy levels for ions from carbon to uranium are computed.

Uncertainty estimates are provided for all calculated energies.

Relativistic and QED effects significantly influence the energy levels.

Abstract

Energy levels of the $1sns$ and $1snp$ states of ions along the helium isoelectronic sequence from carbon to uranium are calculated, with $n=3$-$7$. The computation is performed within the relativistic configuration-interaction method, including the relativistic nuclear recoil effect, the leading QED effects, and the frequency dependence of the Breit interaction. All theoretical energies are supplied with uncertainty estimates.