Atomistic simulations of 1/2⟨110⟩ screw dislocation core in magnesium oxide

Atomistic calculations of the 1/2 < 110 > screw dislocation core structure in MgO have been carried out showing the influence of high pressure (up to 100 GPa) on the core spreading. Calculations rely on a periodic arrangement of dislocation quadrupoles. Comparison between first principles and pairwise potential simulations show a remarkable agreement. Our results confirm that the dislocation core evolves from a spreading in {110} (at low pressure) to a narrower configuration spread in {100} as pressure increases. The periodic dipole method enables us also to record the pressure induced core energy variations. (C) 2014 The Authors. Published by Elsevier B.V.