The atomic energy level structures and transition properties of 1s²2s²2p² ground configuration and 1s²2s2p³ excited configuration in carbon-like ions with Z = 10, 14, 32, 36, 50 are investigated theoretically using the fully relativistic multi-configuration Dirac-Hartree-Fock (MCDHF) method.

Based on the wavefunction constructed with careful consideration of electron correlations, the theoretical calculations are completed by taking into account the Breit interaction, quantum electrodynamic effect and nuclear mass effect. Then the effects of three types of electron correlations, namely valence-valence, core-valence, and core-core correlations, on energy levels are studied in detail, and high-precision excitation energies are obtained. Compared with other theoretical results, the calculated excitation energies for Ne V ion are the closest to the NIST (National Institute of Standards and Technology) data, and the excitation energies of other ions also possess relatively high precision. Additionally, by combining the NIST data and the LS coupled atomic state compositions, the fuzziness in identifying atomic states generated from the code is analyzed, and the corresponding renamed atomic states are presented.

For electric dipole transitions, the transition wavelengths of Ne V and Si IX ions reported in this work are in good agreement with the available NIST data, with the relative errors being less than 0.62%. Their transition ratesaccord well with other theoretical results. And for majority of electric dipole transitions, the electric dipole transition parameters calculated in Babushkin and Coulomb gauges are well consistent with each other, which demonstrates the feasibility and reliability of the MCDHF method for theoretically calculating the energy structures and spectral properties of 1s²2s²2p² and 1s²2s2p³ configurations in carbon-like ions. The results cover a wide range of levels and transitions for carbon-like ions, and the data are expected to enrich the fundamental database for carbon-like ions and provide valuable theoretical references for relevant studies. The datasets presented in this paper are openly available at https://doi.org/10.57760/sciencedb.j00213.00145.