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In this paper we present results of our theoretical studies of the vibrational spectra of ice Ih in the stretching mode frequency range. They include simulation of the infrared and Raman spectra for the OH and OD stretching regions, the effects of a full range of isotopic dilution on the spectra (including polarized Raman spectra) and computational modeling of the observed influence of each dilution step on the properties of vibrationally excited states and on the infrared and Raman spectra. In our calculations we included effects of frequency lowering due to hydrogen bonding, and of intramolecular and intermolecular coupling between bonds. In the crystalline isotopomers the properties of the vibrationally excited states and of the spectra are determined by a complex interplay between the size distributions of the embedded clusters and the intermolecular and intramolecular couplings.

Depending of the sign of the coupling parameter out-of-plane modes can either suppress or promote the splittings.

Theoretical simulation of the ν s stretching band is presented for salicyladehyde and its deuterated derivatives taking into account an adiabatic coupling between the high-frequency O-H(D) stretching and the low-frequency intramolecular O· · ·O stretching modes, linear and quadratic distortions of the potential energy for the low-frequency vibration in the excited state of the O-H(D) stretching vibration, and resonance interaction between the O-H and the C-H stretching vibrations in the aldehyde group. The experimental infrared and Raman spectra of the liquid salicylaldehyde have been recorded. The geometry and experimental frequencies are compared with the results of our HF/6-31++G * * , MP2/6-31++G * * , and Becke3LYP/6-31++G * * calculations.