Calculations of energies, radiative and non-radiative decay rates of triply-excited states in Li-like and B-like nitrogen

The authors report calculations of energies and decay rates for triply-excited 3l3l'3l" configurations in Li-like N, N 4+ , and in B-like N, N 2+ , using a configuration interaction approach. Triply-excited configurations can be obtained in charge-exchange experiments and might be important in the process of neutralization of slow highly-ionized ions at surfaces but nearly no spectroscopic information is available for such states. They have found that there is a very strong configuration mixing in these systems which makes it difficult to give single-particle labels to the terms. This suggests that a molecular (collective) description might be useful in analogy with the molecular model of the doubly-excited nlnl' configurations in He-like spectra. Watanabe and Lin (1987) have considered a molecular description of the 3l3l'3l" configurations in He - . The authors have considered whether this model is useful in the present case where the nuclear attraction is much stronger compared to the interelectronic repulsion but they do not find any compelling evidence for such a description.