Experimental (red) versus scaled harmonic B3LYP-D3/6-31+G* (black) spectra for the three archetypal PAH-C₆₀ adducts used for the scaling factors’ validation: 1AnC₆₀, 2AnC₆₀, and 1PnC₆₀ (Fig. 2). The experimental spectra of the pristine PAHs (light blue) are included to ease the discussion. (a) Spectra built from scaling factors in Table 1. (b) Spectra built from empirical-corrected scaling factors for wavelengths <5 μm (>2000 cm⁻¹) (see the text for more details). The similarity score value for each case is also indicated. The theoretical spectra were constructed in the wavenumber scale by the convolution of a Lorentzian function with FWHM = 4 cm⁻¹ in order to ease the comparison with the experimental spectra.