The two-electron ionisation ladder for He^-²S and H^-¹S

Abstract

The authors have identified and computed the two-electron ionisation ladder (TEIL) of He- 2S with one electron in the 1s shell (up to n=10), and of the coreless but similar system H- 1S. Conditional probability plots show the expected localisation of the valence electrons on the Wannier ridge. For He-, these calculations verify the assignment of the electron-helium resonance spectrum given by Buckman et al. (1983).