Extended MCDHF calculations of energy levels and transition data for N I

TL;DR

This paper provides highly accurate energy levels, lifetimes, and transition probabilities for neutral nitrogen using advanced relativistic atomic calculations, aiding astrophysical spectroscopic analysis.

Contribution

The study presents extensive, highly accurate atomic data for neutral nitrogen using fully relativistic multiconfiguration Dirac-Hartree-Fock and configuration interaction methods, validated against experimental data.

Findings

Theoretical energies agree with experimental data within 0.07%.

Transition probabilities match available experimental and theoretical data well.

Uncertainty estimates show 83 transitions have less than 5% uncertainty.

Abstract

Accurate and extensive atomic data are essential for spectroscopic analyses of stellar atmospheres and other astronomical objects. We present energy levels, lifetimes, and transition probabilities for neutral nitrogen, the sixth most abundant element in the cosmos. The calculations employ the fully relativistic multiconfiguration Dirac-Hartree-Fock and relativistic configuration interaction methods, and span the 103 lowest states up to and including 2s$^2$2p$^2$5s. Our theoretical energies are in excellent agreement with the experimental data, with an average relative difference of 0.07%. In addition, our transition probabilities are in good agreement with available experimental and theoretical data. We further verify the agreement of our data with experimental results via a re-analysis of the solar nitrogen abundance, with the results from the Babushkin and Coulomb gauges consistent to 2% or 0.01 dex. We estimated the uncertainties of the computed transition data based on a statistical analysis of the differences between the transition rates in Babushkin and Coulomb gauges. Out of the 1701 computed electric dipole transitions in this work, 83 (536) are associated with uncertainties less than 5% (10%).