In this class, one can include the calculation of inter­stitial assemblies as well as the complexes built with impurities and vacancies. One then has access to the binding of monoatomic defects to the complexes,2 possibly with the associated kinetic energy barriers.

1.08.3.2.2 Kinetic models

As for perfect crystals, the information obtained by ab initio calculations can be gathered and integrated in larger scale modeling, especially, kinetic models. Many kinetic Monte-Carlo models were thus parameterized with ab initio calculations (see e. g., the works on pure iron25 or FeCu26and Chapter 1.14, Kinetic Monte Carlo Simulations of Irradiation Effects).

1.08.3.2.3 Extended defects

Even ifthe cell sizes accessible by ab initio calculations are small, it is possible to deal with some extended defects. Calculations then often need some tricks to accommodate the extended defect in the small cells. Some examples are given in the next section on stud­ies on dislocations.