Fig. 3: Kinetic events for 〈a〉 screw dislocation core dynamics.

a–f All possible events starting from a P core, a π core or a B core. The dark gray and light gray circles denote atoms on successive \((1\bar{2}10)\) planes. The vertical gray solid lines denote a series of \((\bar{2}020)\) planes; the vertical gray dashed lines are offset with respect to the vertical solid lines by \(\sqrt{3}a/4\). The horizontal gray solid lines denote a series of (0001) planes (Nc planes); the horizontal gray dashed lines are offset with respect to the horizontal solid lines by c/2 (i.e., Nc/2 planes). The “+” symbols denote dislocation core positions and their colors are consistent with those in the first column of g. When two “ + ” symbols are located at the same site, we make one larger than the other for clarity. g The 1^st and 3^rd columns show the starting and ending core structure for one event. The 2^nd column shows the core displacements corresponding to the transitions. Some events listed in the 1^st, 2^nd and 3^rd columns are connected by the gray lines indicating that they are equivalent in the sense that they have the same energy landscapes. The 4^th column shows the irreducible events, where i(κ)j denotes the transition from an i to j core by glide on plane κ.