MOLECULAR DYNAMICS SIMULATION OF THE STRUCTURAL AND PHYSICAL PROPERTIES OF THE FOUR POLYMORPHS OF TiO2

The structural and physical properties of the four TiO2 polymorphs [rutile, anatase, brookite and TiO2 II (alpha-PbO2 structure)] have been calculated by means of molecular dynamics simulation with quantum corrections. The potential model used is composed of the pairwise additive Coulomb, dispersion and repulsion interactions. Energy parameters were determined to reproduce the observed crystal structures of rutile, anatase and brookite, and the measured elastic constants of rutile. Overall, the simulation is successful in reproducing a wide range of properties of the four polymorphs, including the crystal structures, volume compressibilities, volume thermal expansivities, and enthalpy relationships between them.