Abstract
By utilizing transition pathway sampling, we compare the activation energy requirements for homogeneous dislocation nucleation in body centered cubic and face centered cubic crystals. We choose Mo and Cu as representative of the two crystal structures respectively, and investigate the reasons behind the difference between their respective activation energy dependences on stress. In order to explain the influence of crystal structure, we particularly focus on the saddle point configurations corresponding to a series of resolved shear stress values. Transition pathway sampling enables us to determine and compare the stress dependence of activation energy at stresses which are inaccessible to dynamic atomistic techniques.
