In Gao and Yin we can find the Richter-Wang-Ley (RWL) theory for the Raman intensity, that is the theory which is representing the effect of the phonon confinement in the finite crystal domains, as giving the following intensity: 𝐼(𝜔) = ∫ | 𝐶 𝐷 (𝑞)|𝐿(𝜔, 𝑞)𝑑𝑞. 𝐶 𝐷 (𝑞) is the Fourier coefficients of an envelope function. D is the nanocrystal size. 𝐿(𝜔, 𝑞) corresponds to the Lorentzian profile "associated to each Raman active phonon" (Gao and Yin). This model is good for microcrystals but not proper for nanocrystals. Gao and Yin, "considered to analyze the Raman spectra of Si nanocrystals by decomposing Si nanocrystal into four type of Si atoms". We find in their model the one-coordinated Si atoms, Si(1), such as the two-, three-and four-coordinated Si atoms, denoted as Si(2), Si(3) and Si (4). Si(1), Si(2) and Si(3) are related to surface atoms, whereas Si(4) is representing the atoms inside the nanocrystallite core. "Each type of Si atoms can produce a Raman subpeak. The Raman spectrum of Si nanocrystals is a sum of four broadened symmetric Lorentzian subpeaks of Si atoms with different coordination. The ratio of the relative integrated intensity between each two different coordinated Si atoms is proportional to their number of atoms".