Absence of Definite Scaling Laws in Raman Scattering from Fractals
  The frequency dependence of the Raman coupling coefficient $C(\omega)$ is calculated numerically for square and cubic percolation clusters. No general scaling law in terms of the macroscopic parameters such as the fractal dimension $D$ or the spectral dimension $\overline d$ is found. $C(\omega)$ is sensitive to the microscopic structure of the clusters and depends on: site- or bond-percolation, presence or absence of dangling bonds, scattering mechanism and polarization, presence or absence of polarizability disorder. This situation makes the derivation of macroscopic parameters from Raman experiments unreliable. 
P.Benassi, O.Pilla, G.Viliani, G.Ruocco, G.Signorelli, V.Mazzacurati   and M.Montagna