Atomic parameters are fundamental to technological progress and understanding the Universe’s complexity: from nucleosynthesis in extreme astrophysical environments to medical physics applications, including studies of stellar and atmospheric compositions, radiation shielding materials, and diagnostic imaging optimization [1–5].
Among these parameters, atomic energy levels (AELs) are the most essential. All other quantities—transition probabilities, collisional cross-sections (e.g., electron-impact excitations, recombination, dielectronic recombination), Auger rates, and fluorescence yields—depend on them. Thus, accurate and extensive AEL data are crucial to ensure the reliability of derived quantities.
Our group performs large-scale atomic calculations for key r-process heavy elements [2,6,7] using the Flexible Atomic Code (FAC) [8] and AUTOSTRUCTURE (AS) [9], both based on central potentials. FAC employs a spherically averaged potential for all shells, while AS uses scaling parameters for each subshell. A recently developed sequential model-based optimization procedure enhances these calculations, improving efficiency and accuracy across heavy-element systems [6,7]. This poster compares AEL results from FAC and AS, for a few selected lanthanides, under different optimization techniques and explores runtime and memory performance.
All systematically generated data are compiled into a comprehensive database to serve the broader research community.

[1] B.P. Abbott et al., Astrophysical Journal, 848, L13. 2017.
[2] A.J. Levan et al., Nature, 626, 737. 2024.
[3] Akman et al., Radiation Physics and Chemistry, 107, 75–81. 2015.
[4] Polat, R. et al., Annals of Nuclear Energy, 54, 267–273. 2013.
[5] da Silva, A.R., & Smilesnice, R., Astronomy & Astrophysics, 696, A122. 2025.
[6] A. Flörs et al., Monthly Notices of the Royal Astronomical Society, 524, 3083. 2023.
[7] Ferreira da Silva et al., Physical Review A, 112(1), 012802. 2025.
[8] M.F. Gu, Canadian Journal of Physics, 86, 675. 2008.
[9] N.R. Badnell, Astrophysics Source Code Library, ascl:1612.014. 2016.