Densification effects on the Boson peak in vitreous silica: a   molecular-dynamics study
  We perform classical molecular-dynamics simulation to study the effect of densification on the vibrational spectrum of a model silica glass. We concentrate this study on the so-called Boson peak and compare our results, obtained from a direct diagonalization of the dynamical matrix, with experimental Raman data. We show that, upon densification, the position of the Boson peak shifts towards higher frequencies while its magnitude decreases which is in agreement with a recent experimental study. 
P. Jund and R. Jullien