Calculations of the transition energies and oscillator strengths for Cu26+ ion

Non-relativistic energies of 1s(2)2s and 1s(2)np (n <= 9) states for Cu26+ ion are calculated by using the full-core plus correlation method. For 1s(2)2s and 1s(2)2p states, relative discrepancies between our results and high precision results of Yan et al. are within 0.1 ppm. By taking account of the first-order corrections to the energy from relativistic and mass-polarization effects, the higher-order relativistic contribution and QED correction to the energy are estimated under a hydrogen-like approximation. The transition energies, wavelengths and oscillator strengths for the 1s(2)2s - 1s(2)np transitions of the ion are calculated. The results obtained by the three forms are in good agreement with each other.