| Abstrakt: |
Wavefunctions were determined using the multi-configuration Dirac-Hartree-Fock method. The core-core, core-valence, valence correlation, Breit interaction and quantum electrodynamics effects, as well as some higher-order correlation effects, were considered to obtain accurate wavelengths (λ), oscillator strengths (gf) and transition rates (A) of 2s²2p² - 2s2p³, 2s2p³ - 2s²2pnl (n ≥ 3) and 2s2p³ - 2s2p²3s E1 transitions. The branching ratio of 2s2p³ 5So2 (namely Aλ2143.45/Aλ2139.68) based on the latest calculation of 2.462 ± 0.119 is recommended for the determination of a nebula's electron temperature and electron density. The largest calculated gf value of 2s2p³ - 2s²2p4p is λ630.65, differing from that of λ1060.2 (i.e. 2s2p³ ³Po2 - 2s²2p4p ³S1) that was observed with the largest intensities in the Orion Nebula spectrum. In addition, the energy levels and the splittings of 2s2p³, the extremely difficult calculations of the rates of two-electron one-photon transitions as well as those of the very small intercombination A of 2s2p³ 5So2 were studied in detail. Because of the weak spin-orbit interaction, accurately calculating the levels ³Po1,2,0 (or ³Do3,2,1) and their transition matrix elements is very sensitive to relativistic and electron correlation effects. A special case for this is when the transition operators synchronously applied to wavefunctions with regard to 2s2p³ ³Po and 2s²2pnl (n = 4) become extremely sensitive to some higher-order correlation effects. [ABSTRACT FROM AUTHOR] |
