The interaction of screw dislocations with an applied stress was studied by using atomistic simulations together with a continuum treatment of the role which was played by the far-field boundary condition. A finite cell of atoms was used to consider the response of dislocations to an applied stress. This introduced an additional force on the dislocation, due to the presence of the boundary. Continuum mechanics were used to calculate the boundary force which was subsequently accounted for in the equilibrium condition for the dislocation. The lattice resistance curve and the associated Peierls stress were calculated, using this formulation, for screw dislocations in several close-packed metals. As a concrete example of the boundary force method, the bow-out of a pinned screw dislocation was computed and the line tension of the dislocation was calculated from the results of atomistic simulations by using a variational principle that explicitly accounts for the boundary force.

Finite-Sized Atomistic Simulations of Screw Dislocations. V.B.Shenoy, R.Phillips: Philosophical Magazine A, 1997, 76[2], 367-85