Key points are not available for this paper at this time.
For pt.II see ibid., vol.11, no.11, p.1921 (1978). The problem of a hydrogen atom perturbed by a uniform electric field F is analysed. The stability of the level components with the same total quantum number n is investigated. In the limit of small F, energetically lower sublevels are more stable. However, when F increases, this well-known rule is violated for some sublevels at large n. A semiempirical formula for the ionisation probability, which is valid for any arbitrary quantum states, is suggested and discussed.
Damburg et al. (Tue,) studied this question.