Elastic behaviour and lattice vibrations in bcc V and Nb

A model is developed by extending the generalised form of exponential potential known as extended generalised exponential potential to account for: (a) a realistic realization of interactions in all separations in general and that of small separations in particular, (b) Three-body and electronic effects into the interaction in an alternative and simpler form, (c) model free from usual fitting procedure. The model is employed to compute the cohesive energy, phonon spectra and second and third-order elastic constants for group VA bbc metals V and Nb. Thr computed results showing good agreement with the experimental fittings lend reliability and credibility to the potential. (author)