In Fig. , relevant to C 5 , the general aspect is that of dispersed bands with the highest magnitude just below 40 THz. This changes for C 6 (Fig. ), where the highest frequency is closer to 40 THz, corresponding to 1650 cm -1 . This value is exactly in the range of C=C vibrations with a strong signal, i.e., 1625-1680 cm -1 in the molecular state, as listed in the web available "RAMAN Band Correlation Table ", also due to the twice larger amounts of C=C bonds with sp 2 hybridization, there are more flat lines towards the top of the panel and less dispersion of the bands. These features are confirmed upon inspection of the Fig. relevant to C 7 , where the highest bands are flat with the highest line is found around 55 THz corresponding to the short C-C distance of 1.30 Å in the C=C=C subunit also identified in C 3 H 4 propadiene (~1900 cm -1 ).