The Raman peaks given by Harroun et al. are (for comparison with the q-Gaussian centers, in bold within +/-5 cm -1 , and in italic, within +/- In the following, these centers are compared with data from literature (bold, within 5 cm -1 , and italic. within 10 cm -1 ). Caffeine has been already investigated in Here in the following image, the peaks are determined with the first-derivative spectrum. The blue line represents a threshold.