Raman spectra of water in the translational and librational regions

Abstract

A molecular dynamics simulation of the Raman spectra of water in the translational and librational region is presented. Both depolarized and isotropic spectra are calculated at five temperatures in the 250-380 K range and compared with the experimental data. The relevance of ‘collision-induced’ contributions is stressed and in particular the dipole-induced-dipole is shown to dominate the depolarized spectra, whereas contributions to the effective molecular polarizability involving higher order terms in the multipolar expansion account for the low frequency isotropic spectrum. Present results strongly support previous analysis of the experimental data.