Classical chaos in the hydrogen atom near a metal surface

We study the classical electronic motion of the hydrogen atom near a plane metal surface, using the Hamiltonian with exact form of the atom-surface potential. The lz = 0 case is considered. The phase space of the system is separated into the regions of vibrational and rotational motion. Although the system is nonintegrable, for large values of nucleus-surface distance (d > d c = 1.4922 au et E = -1 au) the motion is close to regular in the whole of phase space. However, at smaller distances (d < dc) chaotic trajectories appear. Instability of some trajectories at smaller distances is such that the electron can be captured onto the surface. (Author)