Energy levels, wavelengths, transition probabilities, weighted oscillator strengths, and line strengths for carbon-like ions with Z = 21–30

In this study, the energy levels (E), lifetimes (τ), wavelengths (λ), transition probabilities (A), weighted oscillator strengths (gf) and line strengths (S) among the (1s²)2s²2p², 2s²2p3s, 2s²2p3d, and 2s2p²3p configurations of carbon-like ions with Z = 21–30 were determined using the multiconfiguration Dirac–Hartree–Fock (MCDHF) method. We confirmed the reliability of the energy levels by comparing them with the results of other theoretical methods and experimental observations. The present wavelengths for C-like ions were in good agreement with the previous experimental and theoretical results, with most wavelength differences below 0.8%. Based on the relative deviation (dT) and line strengths (S), respectively, we estimated the uncertainty of the computed transition data. Out of the 1300 transitions computed in this work, 1207 (699) have uncertainties fewer than or equal to 7% as determined by dT (S). We hope these data will be utilized to expand the C-like ion database and provide reference information for experimental studies in plasma experiments.