N-like ions atomic data

Extensive multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations and relativistic configuration interaction (RCI) calculations are performed for 272 states of the 2s^2^2p^3^, 2s2p^4^, 2p^5^, 2s^2^2p^2^3l, 2s2p^3^3l, and 2p^4^3l (l = 0,1,2) configurations in the nitrogen-like ions Cr XVIII, Fe XX, Ni XXII, and Zn XXIV. Valence, core-valence, and core-core electron correlation effects are accounted for through large configuration state function expansions.

Calculated energy levels are compared with data from other calculations and with experimental data from the NIST database. Lande gJ-factors; hyperfine structures; isotope shifts; and radiative electric dipole (E1), electric quadrupole (E2), and magnetic dipole (M1) transition rates are given for all ions. The accuracy of the calculated energy levels is high enough to facilitate identification of observed spectral lines involving the 2l^4^3l' configurations, for which experimental data are largely missing.