One-photon transition probabilities and photoionisation cross section calculations of Be

The states lying in the discrete and the lower continuous part of the spectrum of the manifolds 1,3 S e , 1,3 P e,o and 1,3 D e of the beryllium atom have been obtained by using variational wavefunctions expressed as antisymmetrised products of group functions. While the valence-shell group is described by a rather large number of configurations, only limited polarisation is admitted for the K-shell group. The calculations, made with the aim of obtaining acceptable representations of the resolvent, show satisfactory agreement with all the available experimental data and most recent theoretical calculations. The position and width of several resonances were given with good accuracy by different methods which may be employed with L 2 basis sets.