Infrared spectra of weak hydrogen bonds and indirect damping. On the deep connection between the quantum model and the semi-classical one of Robertson and Yarwood

The classical approximation of the quantum model dealing with the IR spectra of weak hydrogen bond involving indirect damping [B. Boulil, O. Henri-Rousseau, P. Blaise, Chem. Phys. 126 (1988) 263] is obtained. It transforms, via a crude approximation concerning the interpretation of stochastic averages, into the classical Robertson-Yarwood (RY) model [G. Robertson, J. Yarwood, Chem. Phys. 32 (1978) 267].