Ionization of H- by a strong ultrashort laser pulse

We compare the outcome of two different numerical methods aimed at solving the time-dependent Schrodinger equation associated with the interaction of H- with an ultrashort laser pulse. These methods of spectral and configurat ion interaction type are based on an expansion of the total wavefunction on eigenstates of H- built as products of either B-spline or complex Sturmian functions. A careful analysis of our results together with a comparison wi th other existing theoretical data sheds some light on subtle aspects of th e theoretical treatments of H- in a strong laser field. A particular emphas is is put on the crucial role played by the density of states in the contin ua.