Vibrational spectra and valence force field of crystalline V2O5

A complete vibrational study of crystalline V2O5 was performed. Polarized Raman spectra at 300 and 100 K on a single crystal and i.r. absorption spectra on powder samples have been recorded. An assignment in terms of factor group symmetry species is given. A normal coordinate analysis using a complete force field has been performed. All the normal modes of vibration have been described in terms of potential energy distribution and in terms of cartesian displacements. Some modes characteristic of specific bonds have been discussed. Finally some low frequency modes have been found to derive, at a first approximation, from acoustic modes and some dispersion curves are derived from the simple model of the linear chain.