The first-order Raman spectra of CaW${\mathrm{O}}_4$, CaMo${\mathrm{O}}_4$, SrW${\mathrm{O}}_4$, and SrMo${\mathrm{O}}_4$ have been obtained. All theoretically predicted vibrations have been observed, and assignment has been given for the internal vibrations of the tungstate and molybdate ions as well as for the external vibrations involving the rest of the lattice.

• Received 22 November 1966

DOI:https://doi.org/10.1103/PhysRev.157.716