Atomistic simulation of the effect of molecular adsorption of water on the surface structure and energies of calcite surfaces

Abstract

Atomistic simulation techniques using potentials verified against the structure of ikaite, have been employed to study the molecular adsorption of water onto the stepped and planar calcite {104} surfaces as well as the {0001}, {100}, {101} and {110} surfaces. It was found that physisorption of water is energetically favourable on all surfaces although the {104} planes remain the most stable surfaces, and the stepped planes are found to be good models for growth steps on the experimental {104} surface. Experimentally observed 1×1 surface symmetry of the {104} surface is confirmed. On the partially hydrated surface, notionally equivalent carbonate groups are shown to relax differently as inferred by experiment. The hydrated {101} surface shows bulk ordering with rotated carbonate groups in the surface layers in agreement with experimental findings.