The NIST compilation of ionization potentials revisited (I): From He-like to Xe-like ions

TL;DR

This paper revisits the NIST ionization potential database, using a regularized perturbative series to identify inconsistencies and improve the accuracy of ionization potential data across various ions.

Contribution

It introduces a novel regularized perturbative series that matches known asymptotic behaviors and helps validate and correct NIST ionization potential data.

Findings

Identified problematic data points in the NIST database.

Developed a series that accurately models ionization potentials across isoelectronic sequences.

Provided a method for data validation and correction in atomic databases.

Abstract

The National Institute of Standards and Technology (NIST) database on ionization potentials for neutral atoms and ions is examined. For each isoelectronic sequence, we construct a regularized perturbative series that exactly matches the large-$Z$ and $Z\approx N-1$ regions. Comparison of the NIST data with this series allows the identification of problematic values in the reported data.