On temperature dependence of the valence band in the Raman spectrum of liquid water

We propose the model of liquid water as an ideal mixture of small water associates in dynamical equilibrium state for description of the temperature dependence of the valence band shape in the Raman spectrum. The Placzek's theory of vibrational Raman scattering is used for the spectrum simulation. The presented model gives valid results, which are in qualitative agreement with experimental data in the temperature range -20...80°C. We show that clusters consisting of three and four water molecules dominate in the given temperature range, but monomer and dimer concentrations are relatively small at room temperature. Different polarization types of Raman spectra are discussed.