Transition rates and electron correlation effects for the 2s2p2 (4P)3p configuration in N II

Abstract

Based on the multiconfiguration Dirac–Hartree–Fock (MCDHF) method, accurate atomic spectra data including the transition rates, line strengths, and oscillator strengths for the inner-shell excited configuration 2s2p${}^2$ (${}^4$P)3p 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. Meanwhile, by studying the effects of electron correlations on the energy levels and transition rates of 2s2p${}^2$ (${}^4$P)3p configuration, it is found that the valence correlations of active space $nl$ = {$n$ = 2–7, $l$ = s–i} and the core correlations with regard to 1$s^2$ electrons have the strongly adjusted effect and the balancing influence, respectively. Furthermore, the quintet transitions 2s2p${}^2$ (${}^4$P)3s ${}^5$P–2s2p${}^2$ (${}^4$P)3p ${}^5$L${}^{\circ }$ (L = P, D) are found to strictly obey the selection rule $\Delta$S = 0. The branching fractions under this case tend to 1, which is a peculiarly intrinsic property that is recommended to diagnose the lifetimes or rates of quintet states.