COMPUTER MODELING OF INORGANIC SOLIDS AND SURFACES

We have recently performed calculations on a number of inorganic solid s and their surfaces. The emphasis of this work is to understand the r ole of surface defects, either intrinsic defects or additives, in modi fying structure and stability at the atomic scale. The basis of the ap proach is to use energy minimisation to obtain the most stable configu ration. In this paper we describe simulations on NiO which predict tha t the {111} configuration is stabilised by surface oxidation at high t emperatures. Further simulations of calcite model the effect of additi ves on morphology, and we describe the effects of lithium, magnesium a nd hydrogenphosphate additives. We find that both magnesium and phosph ate stabilise the {10 (1) over bar 0} surface while lithium stabilises the basal plane. Finally, we present preliminary work on calcite and barium sulfate which implies that these methods may provide useful ins ights in nucleation and crystal growth at high ionic strengths.