A quasi-classical approach to fully differential ionization cross sections

classical approximation to time-dependent quantum mechanical scattering in the Moller formalism is presented. Numerically, our approach is similar to a standard classical-trajectory Monte Carlo calculation. Conceptually, howe ver, our formulation allows one to release the restriction to stationary in itial distributions. This is achieved by a classical forward-backward propa gation technique. As a first application and for comparison with experiment we present fully differential cross sections for electron-impact ionizatio n of atomic hydrogen in the Erhardt geometry.