FitAik: a package to calculate least-square fitted atomic transitions probabilities. Application to the Er+ lanthanide ion
Résumé
We present a new method implemented in our new package \textit{FitAik}, to perform least-square fitting of calculated and experimental atomic transition probabilities, by using the mono-electronic transition integrals $\langle n\ell |r| n'\ell' \rangle$ as adjustable quantities. \textit{FitAik} is interfaced to the Cowan suite of codes, for which it automatically writes input files and reads output files. We illustrate our procedure with the example of Er$^{+}$ ion, for which the agreement between calculated and Einstein coefficients is found very good. The source code of \emph{FitAik} can be found on GitLab, and the calculated Einstein coefficients are stored in our new database CaDDiACs.