Ab initio calculations showed that a 111 screw dislocation induced a short-range dilatation field in addition to the Volterra elastic field. This core field was modelled in anisotropic elastic theory using force dipoles. The elastic modelling thus better reproduces the atom displacements observed in ab initio calculations. Including this core field in the computation of the elastic energy allowed deriving a core energy which converges faster with the cell size, thus leading to a result which did not depend on the geometry of the dislocation array used for the simulation.

Dislocation Core Energies and Core Fields from First Principles. E.Clouet, L.Ventelon, F.Willaime: Physical Review Letters, 2009, 102[5], 055502