Calculation of Langmuir states in doubly excited helium

We have identified a class of high-lying doubly excited resonance in helium which are directly linked to a classical orbit first proposed by Langmuir for the quantization of helium. The projection of the wave function onto three mutually orthogonal planes is shown to trace the Langmuir orbit. This class of resonances forms the top of the intrashell manifold, and are long-lived compared to other members of the same manifold. In the limit Z→∞, the wave function traces the modified, asymmetric Langmuir orbit generated by bifurcation of the Langmuir orbit