Collective excitations and dynamic structure factor of liquid tellurium

Abstract

Using the potential function and its derivatives evaluated by Rao and Venkatesh from the experimental structure factors, the longitudinal (ω_L) and transverse(ω_T) phonon frequencies have been computed through the equations of Takeno and Goda. The ω_L (k) maximum is found to occur midway between zero and the first peak of the structure factor. The dynamic structure factor has been

calculated in the viscoelastic approximation. In the current correlation function, the position of the maximum of the current density at a particular k is designated as ω_m. ω_m versus k has been obtained at various wave vectors. The ω_m versus k exhibits a flat portion spreading over the three peaks of the complex structure factor of liquid Te even though ω_m (k) increases slowly with k.ω_m gives a peak at nearly the same position as ω_L(k).