DIPOLE-DIPOLE INTERACTIONS IN TUNGSTATES

The vibrationa! spectra of divalent metal tungstates of the form MWO 4, where M = Ba, Sr, Ca, or Zn, have been analyzed in terms of dipole-dipole interactions between adjacent tungstate ions. The van der Waals potential constants determined are of the order of (13-110) ×10 -60 erg·cm6 and approximate those for alkali halides. The present analysis allows for the interpretation of vibrational levels in ZnWO4, which is of a lower symmetry than the scheelites and not previously subject to such characterization.