Energy levels and transition probabilities from the Rayleigh-Ritz variation method: C I and O III

The atomic parameters - energy levels, oscillator strengths, transition probabilities, and transition wavelengths have been presented for electric dipole transitions in C I and O III. The results include center-of-gravity energies of LS-terms of configurations 2s22p2, 2s22p3p for even parity and 2s2p3, 2s22p3s, 2s22p3d for odd parity, and probabilities of the corresponding important electric dipole transitions. The calculations are carried out using the multi-configuration Rayleigh-Ritz variation method with moderate-scale wavefunctions. The oscillator strength values in length and velocity gauges show fair agreement with each other, which indicates that the calculated wave functions are reasonably accurate. The calculated results are compared with existing experimental data. The present values show good agreement with the experimental data. The present transition probabilities should be useful for diagnostics as well as for precise spectral modeling in astrophysical and laboratory plasmas.