Application of molecular dynamics DL_POLY codes to interfaces of inorganic materials

Three recent applications of the DL_POLY molecular dynamics code are described, which demonstrate the flexibility and viability of the code for extending our understanding of the structure, stability and reactivity of ceramics and minerals at the atomic level. The first is an investigation into differences in oxygen atom mobility in bulk and at the most stable {111} surface of ceria. The results show enhanced surface transport but that it is via subsurface oxygen. Secondly, we investigate how polychloro-dibenzo-pdioxins (PCDDs) molecules might adsorb on clay surfaces. The resulting adsorption energies show a clear relationship with chlorine content of the molecule. Finally, we apply DL_POLY to comparing the aggregation of magnesium oxide and calcium carbonate nanoparticles. We find that very small calcium carbonate nanoparticles are amorphous and their aggregation shows no preferred orientation in contrast to magnesium oxide, which remain highly crystalline and combine in a highly structural specific way.