Spontaneous parametric light scattering in Gd$_2$(М$_0$ O$_4$)$_3$

Results are presented on a gadolinium molybdate crystal examined in spontaneous parametric scattering at polaritons; the frequency-angle spectra indicate the dispersion of the ordinary refractive index In the range 350-5000 cm$^{-1}$. The frequencies of the type B$_1$ lattice modes have been determined. Two-particle state bands are observed, which determine the absorption of the crystal in the region around ~1800 cm$^{-1}$.