The room-temperature Raman spectra of LiTa03 for all symmetry phonons are investigated. We make a new assignment of the phonons, which agrees with the selection rules of a C3 symmetry instead of C3V, contrary to Kaminow and Johnston's previous work. The oblique phonon dispersions are obtained and tum out to be consistent with our phonon assignments. We obtain also the polariton dispersion curve and, from it, the lowftequency dielectric constant.
Physical review. B, Solid state. New York. Vol. 13, no. 11 (June 1976), p. 4907-4917