UNDERSTANDING OF MN OXIDE STRUCTURES USING ATOMISTIC COMPUTER SIMULATIONS

Dave Bish and Jeff Post have inspired computational mineralogists to apply state-of-the-art atomistic simulations and to propose new research questions related to clay structures, particularly for manganese (Mn) oxides. Mn oxides are a major player in the geochemical cycles of trace metals due to their high reactivity in electron transfer and cation exchange. Their pioneering X-ray and neutron diffraction work has enabled environmental scientists to understand the high reactivity of Mn oxides based on the crystal structures. There are still ambiguities in the crystal structures of Mn oxides to characterize because of a significant disorder in structural and chemical composition. In this contribution, I present a recent progress of molecular dynamics simulations that has explored the structural disorder in phyllomanganate interlayers and tectomanganate tunnels. Quantum mechanical calculation results are presented to show how metal stable isotopic fractionation can occur during metal adsorption to the interlayers and tunnels of Mn oxides.