Infrared Spectra of the Ices at ≈4 K and the Interpretation of the v OD(D2O) Bands of Ices II and IX

We have studied the infrared absorption by the OD stretching, v OD(D2O), and D2O rotational, v R(D2O), vibrations of fully deuterated ice II and ice IX at lo K, and the absorption by OD stretching vibrations, v OD (HDO), of HDO molecules isolated in ices Ih, II, and IX at 10 K. Calculations of the frequencies and relative intensities of the zero-wave-vector normal v OD(D2O) vibrations of ices II and IX have allowed the v OD(D2O) absorption to be assigned. Each component of the band is broad, even at 10 K, most probably because of Fermi resonance between the fundamental OD stretching vibrational states and the isoenergetic continuum of high-order overtone and combination states of the lattice modes. This work has yielded the most complete interpretation yet achieved of an infrared band due to the OH or OD stretching vibrations of a phase of ice. The far-infrared absorption by the translational vibrations of H2O and D2O ices Ih and Ic at 4.3 K has been measured, and has revealed differences between the spectra of ices III and Ic for the first time. Papers describing this work in full have been published in Journal of Chemical Physics, Vol. 67, No. 4, 1977, p. 1311-18, and Vol. 67, No. 6, 1977, p. 2445-48.