Let us stress that in Fig. , the behaviour of the two q-Gaussians components is determined with the two specific components' central positions established before the fitting procedure. In the case of the left panel of Fig. , these positions are symmetric about the peak at 514 cm -1 , and both at a distance of 3 cm -1 . It could be questionable to assume the plot with these two bands as preferable, with respect to the plot in Fig. , where the sum of the squares of deviations has a lower value. However, in this case (Fig. left panel), we have fixed the positions according information from literature (see .