Impacts into cosmic ice surfaces: A molecular-dynamics study using the Reax force field

We present molecular-dynamics simulations of collisions of cosmic ice mixtures (H2O, CO2, CH4, NH3). Both cluster-cluster collisions and the impact of a Ne ion into a flat target are studied. The Reax force field, which allows for chemical reactions among the species, is employed. We monitor and discuss the reactions occurring as well as the number of radicals, fragments and intermediate reaction products.