答复: [EXTERNAL] Re: dislocation's movement during the minimization

The perfect crystal is responding elastically (energy drops, shear stress stays the same). The dislocation is responding plastically (energy stays the same, shear stress drops). If you make the deformation small enough, you should see the dislocation respond elastically. Alternatively, figure out why the dislocation is relaxing the shear stress so easily. Maybe the dislocation is not fully relaxed to begin with. It could be trapped in a high energy local minimum, with low barriers to more relaxed states.

If so , what can I deal with the system to make the dislocation break away with that local minimum trap ? and how to make sure the dislocation not to fall in another local minimum ?