Spectral mode assignment for binary silicate glasses using molecular dynamics simulations

► Present Fourier filtering of atomic trajectories FFAT method for IR spectral analysis. ► For crystalline and amorphous SiO2 FFAT assignments agree well with literature data. ► Network modification introduces specific IR spectral features.. ► For Na2O2SiO2, both BO and NBO are active in the 1100 cm− 1 and 1200 cm− 1 modes.