End of Atomic Spectroscopy at NIST: Legacy, Achievements, Rebirth

After leading the US research for 120 years, the Atomic Spectroscopy Group (ASG) of the National Institute of Standards and Technology (NIST) was terminated in 2025. For many decades its researchers carried our ground-breaking experiments on spectroscopy of atoms and ions, performed high-precision calculations of atomic structure and collisions, developed sophisticated methods for diagnostics of terrestrial and astrophysical plasmas. Undoubtedly, the most valued activity of the ASG scientists was the production of critically evaluated atomic data and its dissemination via state-of-the-art online databases. Whereas the imminent demise of the group shocked the atomic physics community in the Spring of 2025, the group was nonetheless saved by relocation to NASA Goddard Space Flight Center later that year. The first part of our talk will present the brief history of the group, its major achievements, and its future plans at NASA including the transfer of several experiments and all online atomic and plasma databases. In the second part, the current problems in critical evaluation of atomic spectroscopic data will be highlighted and thoroughly discussed. Special attention will be given to such significant issues as data incompleteness and lack of precise experimental and theoretical data.