Date of this Version
Eigenchannel R-matrix calculations for photodetachment partial cross sections of H–, Li–, Na–, and Aℓ– provide results that are dominated by high doubly-excited states and that are in excellent agreement with available measurements. Propensity rules for doubly-excited states developed for H– apply also for heavier targets. However, states not observed in H– may be observed in the heavier target spectra owing to the non-Coulomb core. Finally the signature of particular doubly excited states changes drastically from one partial cross section to another.