Atomistic simulations of the energetics of dislocation motion in this body-centered cubic structure were carried out by using interatomic potentials which had been derived from first-principles pseudopotential theory. The subjects of the calculations included the (110) and (211) generalized stacking-fault energy surfaces, the Peierls stress which was required in order to move an ideal straight <111> screw dislocation and the kink-pair formation energy for non-straight screw dislocations. Many-body angular forces were accounted for here by means of explicit 3- and 4-ion potentials. The calculated stacking-fault energy surfaces were 10 to 50% higher in energy than those which were estimated by using purely radial-force models. The Peierls stress for an applied <111>{112} shear was estimated to be equal to about 2.5% of the bulk shear modulus. Under a zero applied stress, stable kink-pairs were predicted to form for kink lengths greater than 4 times the Burgers vector magnitude. In the case of kinks that were greater than 15 times the Burgers vector magnitude, the asymptotic value of the kink-pair formation energy was estimated to be 2eV.

Accurate Atomistic Simulations of the Peierls Barrier and Kink-Pair Formation Energy for <111> Screw Dislocations in BCC Mo. X.Wei, J.A.Moriarty: Computational Materials Science, 1998, 9[3-4], 348-56