Results obtained by atomic computer simulation based on an adapted Stillinger–Weber (SW) potential concerning the structure and relative stability of lattice dislocations, tilt and twin boundaries in GaN were considered. The method used for the search and description of all possible atomic configurations depends on the crystallographic structure; consequently it was of general application and the results were transferable to the wurtzite binary compounds. On the contrary, the relaxed structures and their relative energetic stability were potential dependent. The results presented here correspond to a

GaN model described by a pair potential. Whenever possible, the results were compared with experiments or with ab initio calculations. The results included the core shape and energy of, and crystal dislocations of, both edge and screw character; [00▪1] tilt boundaries with misorientation angles ranging from 9.3° (corresponding to Σ37) to θ = 44.8° (corresponding to Σ43) and 4 twin boundaries. The atomic structures of the tilt boundaries could be described in terms of the 3 stable structures of the prism-edge dislocation core. One twin boundary was completely characterized by 6-coordinated channels whereas the other twin boundaries involved more complex structural units.

On the Atomic Structures, Mobility and Interactions of Extended Defects in GaN - Dislocations, Tilt and Twin Boundaries. A.Béré, A.Serra: Philosophical Magazine, 2006, 86[15], 2159-92