Calculation of the Grüneisen parameter by the free-volume approximation method

Abstract

A method for calculating the temperature dependence of the Grüneisen parameter γ of solids in the framework of the free volume approximation is presented. For illustration, the γ values of b.c.c. iron with the Morse potential and f.c.c. neon with the 6–12 Lennard-Jones potential have been computed with the aid of this method. The computed results are in good agreement with those previously evaluated by other methods. Moreover, it is found that the γ values of a lattice depend more strongly on the molecular separation as well as on the curvature of the intermolecular potential well rather than on the dissociation energy of the lattice.