Vibrational spectra and structure of kaolinite: A computer simulation study

The structure and vibrational spectra of kaolinite have been investigated by the joint use of vibrational spectroscopic techniques and of computational methods. The derived potential is based on ab initio calculations of molecular models and tested in normal mode analyses and molecular dynamics simulations. The calculated structural parameters and vibrational spectra are in a good agreement with experimental data. Taking into account the sensitivity of Raman spectra in the lattice region to the structural characteristics, the spectra were examined in more detail, using different models to compute the polarizability tensor of the system. A complete assignment of the bands observed in the experimental spectra is suggested on the basis of the calculated infrared, Raman and power spectra.