Inner-shell excitation energies, transition rates, and autoionization rates of 2s2p ² ( ⁴ P)3d configuration in N II

Based on the multi-configuration Dirac–Hartree–Fock method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excitation configuration 2s2p 2 ( 4 P)3d in N II ion are reported by taking into account the core–core, core–valence, and valence correlation effects as well as the Breit interaction. Good accordance can be found in the comparison with other calculations and measurements. Because the highly excited 2s2p 2 ( 4 P)3d configuration in N II is larger than the N III thresholds 2s 2 2p 2 P[Formula: see text] and 2 P[Formula: see text], there exists an autoionization phenomenon. Also, the autoionization rates of 2s2p 2 ( 4 P)3d are much larger than its radiative transition rates. This causes the energy levels of 2s2p 2 ( 4 P)3d configuration, especially for the triple states 3 P, 3 D, and 3 F, to become considerably instable. In addition, there is strong energy level mixing among the 2s2p 2 ( 4 P)3d configuration and the highly excited configurations 2s 2 2p nl ( n = 6; l = p, f, h) with same even parity. These enable the energy levels and their transition rates to become sensitive to core correlation effect and Breit interaction.