Ab initiocalculations of oxygen diffusivity in group-IB transition metals

First-principles investigations of oxygen transport through Cu, Ag, and Au have revealed subtle changes in the response of the total charge density to the presence of O atoms in the octahedral holes of these metals. In both Cu and Ag, these changes are characterized by a decrease in the magnitude of the curvature of the charge density normal to the metal-metal first-neighbor atoms. In Au there is an increase in the magnitude of this curvature. Associating the curvature of the charge density normal to the internuclear axis with the barrier to oxygen diffusion provides a consistent explanation of the difference in diffusivity of O through Cu, Ag, and Au.