Elastic Behavior and Lattice Vibronics of bcc Phase Metals

Abstract

A model in real space has been developed by extending the generalized form of the exponential potential known as extended generalized exponential potential (EGEP) to account for (a) the correct nature of repulsive and attractive components of forces for all the separations in general and that of small separations in particular (b) the dielectric screening functions in an alternative and simpler form through the parameter m (c) the three-body forces such as volume forces in an indirect way in the framework of EGEP through the parameter n. The model is employed to compute the cohesive energy, phonon spectra and second-order elastic constants in group IV bcc metals. The predictions show good agreement with experimental findings.