Ab initio surface phase diagram of the {104} calcite surface.

Electronic structure calculations, performed at the density functional theory level, were employed to study the surface termination of the {104} calcite surface in contact with a gaseous phase containing water and carbon dioxide. A surface phase diagram was generated to investigate the change in surface termination as a function of temperature, pressure, and gas-phase composition. This diagram revealed that a nonstoichiometric termination could occur in atmospheric conditions at high relative humidity, hence suggesting that nonstoichiometric surfaces can play a major role in the chemistry of calcite surfaces.

Surface structure of (10(-)10) and (11(-)20) surfaces of ZnO with density functional theory and atomistic simulation.

We have calculated the stability of two of the low-index surfaces known to dominate the morphology of ZnO as a function of stoichiometry. These two surfaces are (10(-)10) and (11(-)20). In each case, two terminations only are stable for a significant range of oxygen and hydrogen chemical potential: the pure stoichiometric surface and a surface covered in a monolayer of water.

Atomistic simulation of charged iron oxyhydroxide surfaces in contact with aqueous solution.

Molecular dynamics simulations of aqueous solution/goethite interfaces show that the classical models of the electrical double layer do not accurately describe the distribution of ions near the surface (such a distribution is present even when the surface is neutral) and that the explicit treatment of solvent molecules is essential to capture the effects of the surface on the liquid phase.

Modelling inorganic solids and their interfaces: a combined approach of atomistic and electronic structure simulation techniques.

We are seeking to combine the reliability of the structures and energies obtained from quantum mechanical methods with the insights given by larger scale simulations, which are better able to search configurational space. We will discuss our recent work using quantum mechanical methods, based on DFT, which have been applied to the study of a number of solids. Al2O3, CeO2, MnO2 and CaCO3, and compare these with results using atomistic simulation where the forces between atoms are modelled using interatomic potentials.