The individual IR spectra of conformers are convoluted using a Lorentzian function with a half-width at half-maximum (HWHM) of 10 cm -1 for frequencies below 3200 cm -1 and above 3650 cm -1 , a commonly adopted value. However, for frequencies in the 3200-3650 cm -1 range, corresponding to the O H stretching of phenol aggregates, a Gaussian function with a larger HWHM of 60 cm -1 is applied. This increased broadening accounts for the inhomogeneous effects caused by the complex conformational flexibility of the aggregates. Frequencies below 3200 cm -1 correspond to C H stretching vibrations, while those above 3650 cm -1 arise from free O H stretching in bare phenol and chain-or branched-like aggregates. The large Gaussian broadening in the O H region reflects the structural diversity of the aggregates, which induces significant inhomogeneous broadening.