A density functional theory study of adsorption states of hydrogen molecules on ice surfaces

Abstract

We theoretically investigated physisorption on ice Ih and ice XI surfaces, because the physisorption states of adsorbates play important roles in the chemical reaction on the interstellar medium, which generally consists of ice, with the extremely low temperature (10 K) condition. In this paper, we focused on hydrogen molecules as adsorbates because hydrogen is the most abundant element in space. At first, we briefly reviewed the way to treat the van der Waals interaction in density functional theory. We also showed the calculated adsorption states of hydrogen molecules on ice Ih and ice XI surfaces. We found the non-local correlation functional, which can treat the dispersion interaction, improved the potential energies of physisorbed hydrogen molecules on ice Ih and ice XI surfaces.