Extended calculations of energy levels, radiative properties, and lifetimes for phosphorus-like Se XX

Abstract

Highly accurate calculations are performed for the lowest 151 fine-structure levels arising from the $3s^{2}3p^3$, $3s3p^4$, $3s^{2}3p^{2}3d$, $3s3p^{3}3d$, $3p^5$ and $3s^{2}3p3d^2$ configurations in P-like Se XX using the multiconfiguration Dirac–Hartree–Fock​ and the relativistic configuration interaction methods. Complete and consistent atomic data, including excitation energies, wavelengths, E1, E2, M1, M2 line strengths, oscillator strengths, transition rates, and radiative lifetimes for these 151 levels, are provided. Our data set is compared with the NIST compiled values and other available results. The present data are accurate enough for identification and deblending of emission lines involving the $n=3$ levels and are also useful for modeling and diagnosing fusion plasmas. These data can be considered as a benchmark for other calculations.