A molecular dynamics study on slow ion interactions with the polycyclic aromatic hydrocarbon molecule anthracene

Abstract

Atomic collisions with polycyclic aromatic hydrocarbon (PAH) molecules are astrophysically particularly relevant for collision energies of less than 1 keV. In this regime, the interaction dynamics are dominated by elastic interactions. We have employed a molecular dynamics simulation based on analytical interaction potentials to model the interaction of low energy hydrogen and helium projectiles with isolated anthracene (C14H10) molecules. This approach allows for a very detailed investigation of the elastic interaction dynamics on an event by event basis. From the simulation data the threshold projectile kinetic energies above which direct C atom knock out sets in were determined. Anthracene differential energy transfer cross sections and total (dissociation) cross sections were computed for a wide range of projectile kinetic energies. The obtained results are interpreted in the context of PAH destruction in astrophysical environments. © 2014. The American Astronomical Society. All rights reserved..