  Molecular static simulations have been performed to study the interaction
between a single dislocation and a substitutional Al solute atom in a pure
crystal of Ni. When the Al solute is situated at intermediate distance from the
slip plane, we find that both edge and screw dislocations experiment a
non-negligible binding energy. We show that for such length scale the
description of the elasticity theory can be improved by taking into account the
spreading of dislocation cores via the Peierls-Nabarro model.
