Structural dynamics of water and its dielectric and absorption spectra in the range 0-800 cm− 1

A structural dynamics model is suggested that describes the complex permittivity and absorption spectra of water over the entire range of orientation polarization, 0 < ν < 800 cm− 1. The mechanism of elementary motion of water molecules involves partial “dissociation” of some fragments of the tetrahedral network. Structural fragments are differentiated in which molecules rotate about different axes and have different moments of inertia. The experimental complex permittivity and absorption spectra were described using the confined rotator (I)/…/ confined rotator (N) theoretical scheme. The frequency boundary between the collective Debye process and quasi-resonant processes related to elementary water motions was thereby determined. The common features and differences between the spectra of ordinary and heavy water are explained for the entire frequency range. This data made it possible to provide a new interpretation of the band at ∼ 200 cm− 1. Spectral trends in the frequency range 5 < ν < 200 cm− 1 are steered by the structural transitions of separate molecules and dimers realized in rotational-translational diffusion processes.