The goal of this project is to understand mineral lattice processes that give rise to the elastic, thermodynamic and transport properties of minerals. Calculations have been completed for specific heat of forsterite which agree well with values obtained by calorimetry. The calculations for forsterite will now be extended to include thermal expansion, compressibility , and the pressure and temperature dependence of the elastic constants. A similar study will be carried out on fayalite and perovskite. These mineral are major phases in the earth's mantle and knowledge of their properties will facilitate interpretation of seismic data.