Hyperfine structure and 2s-2p transition in C-like Fe, Co and Ni

Energy levels, hyperfine structure and 2s-2p radiative transition processes of C-like Fe, Co and Ni are studied by performing multiconfiguration Dirac–Hartree–Fock method using the fully relativistic codes GRASP2K. Electron correlation effect on the energies, hyperfine structure constants and radiative transition rates are investigated in detail. Influences of Breit and quantum electrodynamics (QED) effect on energies are studied. Good agreements are found between the results in this work and experimental data. The radiative spectra of the excited states 1s22s2p3 and 1s22p4 of C-like Fe, Co and Ni may provide theoretical support for further experimental study. Since Fe, Co and Ni are important constituent part of experimental apparatus (such as EBIT), the data in this work have important application value for experimental application.