Multielectron effects in strong-field ionization of benzene derivatives

Strong field ionization of benzene, fluorobenzene, benzonitrile and 1-chloro-2-fluorobenzene, is studied within the framework of real-space and real-time time-dependent density functional theory. Analysis of the ionization rates as function of the molecule orientation, reveal significant multielectron contribution from inner Kohn-Sham orbitals that depends on the electronic structure and on the orbital symmetries of the molecule, as well as on the polarization and intensity of the external laser field. Calculated photoelectron angular distributions at different molecule orientations and in response to laser fields with different degree of ellipticity, further demonstrate the spatial dependency of the orbital ionization rates.