We extend a quantum non-adiabatic treatment of damped weak H-bonds involvin
g Fermi resonances (D. Chamma, O. Henri-Rousseau, Chem. Phys. 248 (1999) 91
-104) in order to account for stronger H-bonds. For this purpose, we introd
uce in the model the quadratic dependence of both the angular frequency and
the equilibrium position of the X-(H) over right arrow ... Y stretching mo
de on the intermonomer (X) over left arrow-H ...(Y) over right arrow motion
s. We obtain the spectral density corresponding to this Hamiltonian by Four
ier transform of the autocorrelation function of the dipole moment of the f
ast stretching mode. This paper goes beyond a step toward a more comprehens
ive theory of infrared bandshapes of H-bonded systems. Further development
should lead to the release of a modeling software in this field. (C) 2000 E
lsevier Science B.V. All rights reserved.