where ⟨ ḋ(τ ) ḋ(τ + t)⟩ τ is the autocorrelation function (ACF) of the dipole moment time-derivative ( ḋ), t the is time, and ν is the frequency. Other types of vibrational spectra, such as Raman or vibrational circular dichroism, can The quantum-chemical approximation used for simulation was PBE/def2-SVP. All values given are in m -1 (for conversion to cm -1 , the values must be divided by 100). All the MD values were obtained from the MIITO routine.