Computer simulation of core structure and Peierls stress of dislocations in anthracene crystals

Abstract

The equilibrium configuration for the core of a (010) screw dislocation in an anthracene crystal was calculated using the atom-atom potential method. It was strongly anisotropic and complicated due to the characteristic shape and dimension of the molecule. The core region did not spread as much as that of a (010)(001) edge dislocation. Its energy was lower than that of the edge dislocation. The Peierls stresses of both the edge and the screw dislocations were estimated by means of gradually increasing an external shear stress; that of the screw dislocation was much larger than that of the edge dislocation.