  The classical dynamics of two electrons in the Coulomb potential of an
attractive nucleus is chaotic in large parts of the high-dimensional phase
space. Quantum spectra of two-electron atoms, however, exhibit structures which
clearly hint at the existence of approximate symmetries in this system. In a
recent paper,(Phys. Rev. Lett. 93, 054302 (2004)), we presented a study of the
dynamics near the triple collision as a first step towards uncovering the
hidden regularity in the classical dynamics of two electron atoms. The
non-regularisable triple collision singularity is a main source of chaos in
three body Coulomb problems. Here, we will give a more detailed account of our
findings based on a study of the global structure of the stable and unstable
manifolds of the triple collision.
