Transition energy and dipole oscillator strength of 1s 2 3d-1s 2 n f transitions for Sc 18+ ion

The transition energies of the 1s 2 3d-1s 2 n f (4⩽ n ⩽9) transitions and fine structure splittings of 1s 2 n f ( n ⩽9) states for Sc 18+ ion are calculated with the full-core plus correlation method. The quantum defect of 1s 2 n f series is determined by the single-channel quantum defect theory. The energies of any highly excited states with n ⩾10 for this series can be reliably predicted using the quantum defect as function of energy. Three alternative forms of the dipole oscillator strengths for the 1s 2 3d-1s 2 n f ( n ⩽9) transitions of Sc 18+ ion are calculated with the transition energies and wave functions obtained above. Combining the quantum defect theory with the discrete oscillator strengths, the discrete oscillator strengths for 1s 2 3d-1s 2 n f ( n > 9) transitions and the oscillator strengths densities corresponding to the bound-free transitions are obtained.