New Potential Energy Functions for Diamond and α-Tin Crystals

A new model of potential energy functions for atomic solids is given and applied to diamond and α-tin crystals. In the new model, a factor expressing the characters of covalent bonds has been included. Therefore it is suitable for covalent crystals. New pontentials of C and α-Sn crystals accurately reproduce experimental elastic constants and phonon dispersion curves and so on. The set of new potentials is accurate enough for computer simulations.