Résumé
The vibrational properties of silica glass have been intensively studied experimentally andtheoretically during the last four decades. However there are few theoretical studies of theevolution of the vibrational properties under pressure.We have calculated the parallel and perpendicular Raman spectra of the vitreous silica. The studyhas been carried out using first principles calculations within the density functional theoryframework. The calculated spectra at ambient pressure are in good agreement with theexperimental ones as well as with previous calculations reported in the literature. Themodifications of the Raman spectra under pressure also reproduce the experimental data. Apreliminary analysis of the resulting structural modifications and their correlations with the changesseen in the spectra will be reported.