Infrared and Raman spectroscopic features of clinochlore Mg6Si4O10(OH)8: A density functional theory contribution

Mineral identification and analysis are often performed by using vibrational spectroscopies, namely infrared and Raman techniques. However, very few spectroscopy data are available on clinochlore, an important phyllosilicate with manifold applications in several fields. In the present work, ab initio Density Functional Theory simulation was employed to calculate the infrared and Raman spectra at Γ points and the phonon dispersion at different k-points of the magnesium end-member of clinochlore, with ideal chemical formula Mg6Si4O10(OH)8 and space group C2/m. Each phonon mode of the mineral was assigned to specific vibrations of the ionic groups in the structure. The theoretical results were found in good agreement with the available experimental data in literature, further extending the knowledge on the vibrational properties of clinochlore, which could be useful for experimental characterization of this mineral phase in various and different fields of research.