Figure 3
From: Direct experimental observation of weakly-bound character of the attached electron in europium anion
Schematic of energy levels in neutral and anionic Eu observed in the experiment.
The energy levels of the neutral Eu are obtained from Ref. 43, while those of the anionic Eu are acquired from the present experiment. The EA of Eu is defined as the energy difference between the lowest energy levels of the neutral and the anion. Leading electronic configurations and LS terms are included.
