Photoionization of atoms using time-dependent density functional theory

Time-dependent density functional theory appears to be a valuable tool to study multiphoton ionization of atoms or molecules. However, some difficulties appear for high laser intensities, when multiple ionization becomes possible. Photoionization of atoms subjected to an intense laser pulse is studied within this framework. In order to gain some insight into the dynamics of the process, the kinetic-energy spectra of the emitted electrons are analyzed. Particular attention is paid to the problem of extracting the photoelectron spectra from density functional theory calculations. A method to compute the spectra from the electron density is proposed.