Figure . The grey line is giving the data obtained from COSmIC pyrene-generated nanograins. Using Lorentzian and Gaussian components, Gavilan and coworkers determined six bands; the positions of their centers are here given by the black lines. In general, the decomposition of Raman spectra can be improved by using q-Gaussians, instead of Lorentzian and Gaussian functions (see . According to the experimental results given in the mentioned references, Gavilan and coworkers conclude that "The Raman spectrum of the COSmIC nanograins is typical of disordered carbons. A D band (D1) is found centered at 1387 cm -1 , a composite G band (G+D2) centered at 1588 cm -1 , and a D3 band in-between at 1523 cm -1 ". "The narrow X band in Table can be attributed to a minor G (sp 2 ) band seen in graphitic amorphous carbons originating here from intermediate products of the growth of pyrene to larger PAHs in COSmIC" .