Fragmentation of H2+ in strong 800-nm laser pulses:: Initial-vibrational-state dependence -: art. no. 043405

The fragmentation of the H-2(+) molecular ion in 25-fs, 800-nm laser pulses in the intensity range 0.05-0.5 P W/cm2 is investigated by means of wave-packet propagation calculations. We use a collinear reduced-dimensionality model that represents both the nuclear and electronic motion by one degree of freedom including non-Born-Oppenheimer couplings. In order to reproduce accurately the properties of the "real" three-dimensional molecule, we introduce a modified "soft-core" Coulomb potential with a softening function that depends on the internuclear distance. The analysis of the calculated flux of the outgoing wave packets allows us to obtain fragmentation probabilities and kinetic-energy spectra. Our results show that the relative probabilities for dissociation and Coulomb explosion depend critically on the initial vibrational state of the molecular ion.