The predicted full DG spectrum in the 3−8   μm C-H stretching and bending and C-C mode region as a function of X_H calculated using the structural de-composition described in Sect. 2.2.3 and the data in Table 2. Here the spectra are normalised to the strongest band for each value of X_H. On the left the strongest bands are for high X_H > 0 (green to brown), while the opposite is true for the longer wavelength bands on the right (shortward of 6.8 μm). The data with error bars and the shaded areas indicate the diffuse ISM bands as per Figs. 8 and 9.