We study the feasibility of our empirical potential to dislocation formation and its contribution to structural stability in Ga(x)A(1-x),,. The feasibility is exemplified by the calculations of the dislocation core energy and core radius for various dislocation core structures in wurtzite structured GaN. Moreover, we carry out theoretical analyses of the structural stability for GaNxAs1-x with dislocation whose core structure is described by five- and seven-coordinated channels (5/7 core) over the entire concentration range. The GaNxAs1-x.changes its structure from zinc blende to wurtzite at the concentration for phase transition x(c) = 0.3 with dislocation and x(c) = 0.4 without dislocation. This is because the 5/7 core favors the wurtzite structured GaNxAs1-x with lower core energy than that in zinc blende structured GaNxAs1-x. (c) 2004 Elsevier B.V. All rights reserved.