Pre-stellar grains of dense molecular clouds consist of dust particles of silicates/carbonaceous materials covered by ice mantles, mainly of H2O but also of other volatile species such as CO, CO2, NH3 and CH3OH. These mantles provide the surfaces where reactions of astrochemical relevance can occur. Grain surface reactions take place through successive elementary steps: adsorption, diffusion and reaction of the reactants, and desorption of the products.
The thesis project aims at simulating, by means of quantum chemical methods, the diffusion and reaction steps involving atoms (i.e., H, O, N and C) and light radicals (i.e., OH, NH2 and CH3) that lead to the formation of interstellar compounds. The main goal is to provide a molecular description of the simulated processes, including unique, highly accurate energetic information, which will be of high value for the purposes of the ACO project and teams.
The thesis is part of the ACO network, whose ultimate goal is to reconstruct the early history of the Solar System by comparing presently forming solar-type planetary systems with its small bodies. The comparison will be based on the most advanced astrochemical knowledge, which will be developed by the interdisciplinary ACO team.