Hyperfine Structures ab-initio Calculations of the 2p4(3P)3d2S+1LJ States in the Fluorine Atom

In previous work devoted to ab initio calculations of hyperfine structure constants in nitrogen and fluorine atoms, we observed sizeable relativistic effects, a priori unexpected for such light systems, that can even largely dominate over electron correlation. We observed that the atomic wave functions calculated in the Breit-Pauli approximation describe adequately the relevant atomic levels and hyperfine structures, even in cases for which a small relativistic LS-term mixing becomes crucial. In the present work, we identify new levels belonging to the spectroscopic terms 2p⁴(³P)3d^2;4(P; D; F ) of the fluorine atom, for which correlation effects on the hyperfine structures are small, but relativistic LS-term admixtures are decisive to correctly reproduce the experimental values.