The core structure of dislocations in Al: a critical assessment

The core structure of dislocations in Al has been the subject of various recent investigations. Whereas atomic simulations, which must rely on empirical potentials, are not very reliable, the generalized Peierls model using ab initio misfit energy values from electron density functional theory is able to give accurate results, when appropriate methods are used and in the calculations certain basic conditions are satisfied. It is shown that discrepancies in the results obtained in the literature result from inappropriate choice of trial functions in the variational problem for the dislocation energy and from incorrect treatments. Due to its inherent approximations the Peierls model can give only order of magnitude values for the Peierls energy.