Extended generalized exponential potential and elastic behaviour of FCC metals

Abstract

The generalized form of exponential potential has been suitably extended to represent the correct nature of repulsive and attractive components of the forces for all the separations in general and that of small separations in particular. An additional parameter n is introduced to account for the multibody interactions in an indirect manner to some extent. The parameter m accounts effectively for the exchange and correlation effects due to electrons. The efficacy of the potential so developed has been tested by computing the second-and third-order elastic constants of Rh, Yb, Ir and Th for which Cauchy discrepancies are insignificant. Further, the pressure derivatives of the second-order elastic constants of the mentioned metals have also been computed. Finally, the potential is used to predict the cohesive energies of the mentioned metals which show remarkable agreement with the experimental values and thus establishing the empirical nature of the potential.