  Cohesive zone models provide an illuminating and tractable way to include
constitutive nonlinearity into continuum models of defects. Powerful insights
have been gained by studying both dislocations and cracks using such analyses.
Recent work has shown that as a result of the locality assumption present in
such cohesive zone models, significant errors can be made in the treatment of
defect energies. This paper aims to construct a non-local version of the
Peierls-Nabarro model in which the atomic level stresses induced at the slip
plane depend in a non-local way on the slip degrees of freedom. The non-local
interplanar kernel is computed directly from atomistics and is used to evaluate
both the structure and energetics of planar dislocations. The non-local
formulation does not significantly change the dislocation core structure from
that obtained with the local model, but the new formulation leads to
significant improvements in the description of dislocation energetics for
dislocations with planar cores.
