Ionization dynamics ofC2H2in intense laser fields: Time-dependent Hartree-Fock approach

Abstract

We investigate the multielectron ionization dynamics of C2H2 subjected to intense few-cycle laser fields with the time-dependent Hartree-Fock approach, in which one-center method is employed with the finite-element discrete-variable representation and B-spline functions. It is found that, when the photon energy is close to the energy gap between the two inner orbitals, an inner-orbital single-photon resonant transition phenomenon occurs and plays an important role in the ionization process of the molecule. Furthermore, the ionization of inner electrons surpasses that of the electrons in the highest occupied molecular orbital (HOMO) at high laser intensities, which may be attributed to the effect of the spatial distributions of molecular orbitals. Moreover, this phenomenon will be enhanced by a reduction of the screen for electrons in the HOMO due to the ionization of inner electrons.