A Critical Survey of the Low Configurations in Be I-like Spectra

Abstract

Available measurements of the transitions 2s2-2s2p and 2s2p-2p2 are examined as to their iso-electronic consistency by studying appropriate functions of the transition energies of 2s2 1S0-2s2p1P1, 3P1, 2s2p1P1-2p2 1D2, 1S0 and 2s2p3P2-2p2 3P2, and by deriving semi-empirical screening formulae for the fine-structure intervals of the 3P terms. In this way, accidental experimental errors are smoothed out and missing data are determined by interpolation. The results of the analysis are comprised in a table of recommended level values, extending to Z = 26 or, for 2s2p1P1, 3P1, to Z = 28. A comment on our recent discussion of the Li I-like spectra is appended.