Accurate line strengths, transition rates and lifetimes of 2s2p2(4P)3s in N II

Abstract

Abstract The accurate line strengths, transition rates, oscillator strengths, and lifetimes from the inner-shell 2s2p2(4P)3s states 5P and 3P of N II are reported within the framework of the multiconfiguration Dirac-Hartree-Fock (MCDHF) method. The effects of core-core, core-valence, and valence correlations; the Breit interaction; and QED effect are taken into account. Through investigating the influences of electron correlation effects on the quintet states, it is found that the core correlation effect has certain compensation effect in accurately optimizing the line strengths, transition rates and lifetimes of quintet states; the branching fractions of 2s2p3 5S$^\circ _{2}$–2s2p2(4P)3s 5P1, 2, 3 tend to 1, which is inferred as a peculiar intrinsic property that can be useful for plasma diagnostics; unlike 3P0, 1, 2 and 5P1, 3, the calculations of lifetime of 5P2 show some J-dependence, and the velocity form calculations for this J=2-dependence are much more sensitive to electron correlations of 1s22s2p2(4P)3l (l = p, d) than those in the length gauge, which will be helpful to deal with the calculations of lifetime with J=2-dependence in the carbon like isoelectronic series.