Theoretical investigation of transition data in SI

Uncertainties in the oscillator strengths of specific lines used for abundance analyses directly translate into uncertainties in the derived elemental abundances; and incomplete or biased atomic data sets can impart significant errors in non-local thermodynamic equilibrium modelling. Theoretical calculations of atomic data are therefore crucial to supplement the limited experimental results.

In this work, we present extensive atomic data, including oscillator strengths, transition rates and lifetimes, for 1,730 electric dipole (E1) transitions among 107 levels in neutral sulphur (SI) by using the multiconfiguration Dirac-Hartree-Fock (MCDHF) and relativistic configuration interaction (RCI) methods. These levels belong to the configurations 3p^3np (n=3-7),3p^3nf (n=4,5), 3s3p^5, 3p^3ns (n=4-7), and 3p^3nd~(n=3-6).