The ice/water interface: orientational order parameters for the basal, prism, {202̄1}, and {21̄1̄0} interfaces of ice Ih

Abstract

Orientational order parameters for four crystallographically distinct ice/water interfaces are defined and measured in molecular dynamics computer simulations of the CF1 central force model of water. We find that all interfaces are broad, with consistently different orientational structures found among the four interfaces. We also define and measure a local order parameter in the interfaces related to oxygen–oxygen coordination number, and show that this measure of the interfacial width is extremely broad. Combining recent results for the translational order parameters, average density order parameters and diffusion coefficient order parameters, for this model of water, coupled with other simulations of rigid models of water, a clear picture of the structure of the ice/water interface emerges. This also reveals a possible explanation for the differential accumulation of certain solutes at the ice/water interface.