IR spectral density of weak H-bonded complexes involving damped Fermi resonances. II. Numerical experiments and physical discussion Original Research Article

The IR absorption band profile of the X–H stretching mode of weak H-bonded complexes involving Fermi resonances between the high frequency mode and some bending modes, all these modes being damped, have been computed within the linear response theory, by aid of the Fourier transform of the autocorrelation function of the dipole moment operator of the high frequency mode [O. Henri-Rousseau, D. Chamma, Chem. Phys. 229 (1998) 37]. As it appears the probability to observe realistic and noticeable modifications of the experimental lineshapes by Fermi resonances is strongly enhanced by the presence of an hydrogen bond, leading to the conclusion that Fermi resonances must play a very general role in the lineshapes of H-bonds.