Position and widths of autoionising states in the helium isoelectronic sequence above the N=2 continuum

Doubly-excited state resonances of the helium-like nitrogen ion N5+ near then=3 threshold of N6+

“…Our results are in good agreement with the calculations of Ho [9], Oza [12], Bachau [10], Hugo et al [13] and Bachau et al [14]. In addition to the total width, of interest are the partial widths corresponding to the decay of resonances through the open channels lskp, 2skp, 2pks and 2pkd (see Ta-bles 4, 5).…”

“…Excitation energies are given in Tables 1 and 2 with results of others authors 0.20-10 -3 0.32.10 6 0.0012 [9][10][11][12][13][14]. For singlets 1p(-) and triplets 3p(-) states, our results agree well with the others results.…”

“…As examples, we notice the calculations made by Ho [7][8][9] using the complex coordinate rotation method, by Bachau [10] using the truncated diagonalisation method, by Oza [11][12] using close-coupling method, and by Hugo et al [13] using the B-spline method. More recently Bachau et al [14] have calculated all these characteristics together with partial widths using the pseudo-potential Feshbach method (PPF).…”

A simple formula for the energies of doubly excited states

“…We note that the equation has In Table I we show the comparison of energy levels calculated using eq. (5) with those obtained from the CI calculations of Bachau [11]. We note that the agreement in all cases is better than one electron volt.…”

Subgroups of Profinite Groups Acting on Trees

“…The energies of the 06+(4, 4) levels spread over 10 eV and are comparable to the energy limit of the 06+(31, nl') series. The lower states lie below the O"(31) threshold and thereiore autoionize to the @i, k i j continua, whereas the upper siates autoionize preferentially to the (31, kl') continua (Bachau 1984). In the typical situation presented in figure 1, a (4,4) resonant level crosses the (31) threshold at about R = 10 au; using the characteristic partial width associated with the decay to (2l, kf') open channels one can estimate the total amount of decay to these continua; it is about 10% for a collision velocity U = 0.2 au.…”