The lattice-dynamics calculations for the paraelectric phase of the Sn2P2S6
ferroelectric are performed within the model of rigid ions. The model para
meters were chosen by fitting the calculated phonon spectra to the known da
ta on inelastic neutron scattering. The dispersion curves obtained were the
n used for calculating the orientational dependences of sound velocity and
the variation of the phonon frequencies under the hydrostatic compression.
The data obtained an in good agreement with the experimental results. (C) 2
000 MAIK "Nauka/Interperiodica".