Density functional theory study of neutral, singly, and multiply charged Polycylcic Aromatic Hydrocarbon molecules

We have studied multiply ionization for a range of Polycyclic Aromatic Hydrocarbons (PAHs) and their charge dependent stabilities with respect to H−, H+-, C2H2- and C2H2+-emissions by means of Density Functional Theory. The adiabatic dissociation energies reveal information about the competition between these channels as functions of PAH charge state and provide predictions of the thermodynamical stability limits, while the sequences of ionization energies may e.g. be used to extract absolute ionization cross sections of astrophysical relevance.