Critical Evaluation of Atomic Data

Introduction: Accurate laboratory atomic data on spectral lines’ wavelengths, energy levels, and transition probabilities (or oscillator strengths) are inevitably important for several research fields and applications, for example, in the field of astrophysics and plasma physics, and for fundamental and technological applications, in which spectra and their modeling are a part. However, most of the laboratory data (experimental and theoretical) are often present in dissimilar formats, widely dispersed/scattered in the literature, and the literature may contain several values for a quantity that disagree greatly, leading to debate about what is best, most reliable, and final value. Critical evaluations of these data sets play a significant role in such cases.

Methods: Several statistical tools and techniques are available to compare and evaluate data from different sources, including modern-level optimization schemes such as LOPT. For theoretical support, extended HFR calculations were performed using Cowan’s codes. For evaluation of the transition probabilities (TP), multiple comparison schemes are generally carried out based on their dS = (S₁/S₂) as a function of line-strengths for a set of transitions with similar accuracy.

Results and Discussion: This work focuses on comprehensive spectral data analysis and their evaluations, including theoretical TP evaluations on spectra of some selected atoms/ions that we have recently compiled, including C II, Au IV, Cs XI, and Kr VI, and Si II.

Conclusion: In this work, the shortcomings of the existing atomic data are discussed, and, accordingly, the importance of critical evaluation of atomic data is demonstrated with specific examples.