The 1/3<11▪0> edge dislocation was present in the GaN layers. Its atomic core was described by 3 configurations, 5/7, 8 and 4 atom rings. Besides the isolated dislocations, this dislocation was involved in the intrinsic structure of coincidence <00▪1> tilt grain boundaries. Here, the atomic structures based upon the 3 cores and the associated energies of this dislocation, in a Σ = 7 grain boundary, were calculated using ab initio code. The values of energies and bond lengths were compared with the values previously obtained by using an empirical potential and a tight-binding method.Atomic Structure of Dislocations in Nitride Semiconductors. S.Petit, A.Béré, J.Chen, I.Belabbas, P.Ruterana, G.Nouet: Physica Status Solidi C, 2006, 3[6], 1771-4