The temperature variation of the Debye-Waller factor is calculated for copper on the basis of the anisotropic dispersive continuum model. The results are compared with x-ray measurements of Flinn et al. and the other theoretical calculations of this factor from different Born-von Karman force models. The Debye-Waller factor is not very sensitive to the details of the frequency spectrum. The frequency distribution function for vanadium is also calculated on the basis of the anisotropic dispersive continuum model. The results of this calculation, as well as many other force-model calculations, yield a poor representation of the frequency spectrum, for which experimental measurements from the inelastic incoherent neutron scattering techniques ...