Raman and infrared study of the low temperature phase of solid H2S and D2S

Raman, infrared and far infrared spectra of polycrystalline samples of H2S and D2S at 80 K and 18 K have been recorded. Many new features have been detected, including some very low frequency Raman modes. The assignments of these and other peaks are discussed in terms of the known crystal structure and compared with previous results. The spectra are in general compatible with the low symmetry and unusually large unit cell of this molecular crystal. The principal features are described qualitatively in terms of interactions involving the four hydrogen bonds linking each molecule in the two dimeasional network.