Theoretical oscillator strengths for the beryllium 1s22s21S-1s22s2p1P0, 1s22s2p1P0-1s22p21D and 1s22s2p1P0-1s22p21S isoelectronic sequences

Abstract

Accurate oscillator strengths (f-values) for the 1s22s2 1S-1s22s2p 1P0, 1s22s2p 1P0-1s22p2 1D, 1s22s2p 1P0-1s22p2 1S lines of the Beryllium sequences are calculated using wavefunctions (the 'charge wavefunctions' Psi c) containing all of the specifically non-closed shell type correlation effects given by Sinanoglu's (1970) non-closed shell many electron theory (NCMET). Comparison with the numerous Beam-Foil experimental results using both the dipole length and dipole velocity formulae, yields very good agreement except for the Be I 1s22s2p 1P0-1s22p2 1S line. For this line, the dipole length and velocity calculations yield fR=0.396, fV=0.100 while two experiments give f=0.122 and f=0.119.