An ångström-sized window on the origin of water in the inner solar system: Atomistic simulation of adsorption of water on olivine

The origin of water in the inner solar system is not yet well understood. Because of the coexistence of water and small solid particulates in the accretion disk from which our planetary system formed, we propose that adsorption of water onto the surfaces/pores of forsterite could play and important role in the delivery of water to the rocky planets. In this work we employ energy minimization techniques to understand the surface energy structure and the distribution of surface adsorption sites for the {0 1 0} and {1 0 0} planes in forsterite. This study indicates that most of the surface area is not involved in the initial adsorption of water molecules and that the stronger adsorption sites coincide with the most underbonded surface Mg atoms.