Diffusion and Dissociation of Water on Forsterite Surface

Abstract

To investigate the effects of forsterite structure on processes of H₂O decomposition and proton diffusion, we performed molecular dynamics calculations on forsterites in glassy and crystalline states. The result shows that the decomposition rate of H₂O on forsterite in the glassy state is higher than that in crystalline state in a temperature range of 200 to 400 K. Furthermore, the decomposed proton permeates into the internal part of glassy forsterite through hopping, whereas no permeation was observed for the crystalline state. These results suggest that the glassy structure of forsterite is an important factor for chemical evolution processes in interstellar spaces.