where we have a weighted sum over phonon wave vectors and branches, of Lorentzian broadened phonon lines. Function 𝐶 (𝑞, 𝜔 𝑗 (𝑞)) is the Raman coupling coefficient, whereas 𝐹(𝑞) is a phonon wave-vector "uncertainty". The boson occupation factor is n(ω). In this equation, as shown by Nemanich and coworkers, we can find the dynamical structure factor for Stokes scattering, in origin the Fourier transform of the correlation function of fluctuations in the polarizability. The Lorentzian broadening, with a lifetime Γ for phonons, is substituting the δ function in the dynamical structure factor. In amorphous materials the intensity is given by the Shuker-Gammon formula, 1970: