Transition energy and oscillator strength of Sc¹⁸⁺ ion

The transition energies and the dipole oscillator strengths for the 1s²2s--1s²np (2≤n≤9) and 1s²2p--1s²nd (3≤n≤9) of lithium-like Sc¹⁸⁺ ion are calculated by using the full core plus correlation method. The fine structure splittings of 1s²np and 1s²nd (n ≤9) states are determined from the expectation values of spin-orbit and spin-other-orbit interaction operators. The quantum defects of these series, as function of principal quantum number n, are obtained. The agreement between the f-values obtained from three alternative formulae is excellent. Comparisons of our results with experimental data available in the literature are carried out.Combining the single-channel quantum defect theory with the discrete oscillator strengths obtained in this work, this paper obtains the behaviour of discrete oscillator strengths and oscillator strength densities corresponding to the bound-free transitions adjacent to ionization threshold.