On the series of double-excited states for the H-ion below the N=3 threshold

The arrangement of resonances in series converging exponentially to the threshold N=3 has been investigated. The authors examine the level of agreement between the numerical results below N=3 threshold by various authors and the conclusion (Gailitis and Damburg 1963) that the ion H - below all thresholds N to 2 have series of resonances obeying an exponential relationship.