The most important tools for structure defects analysis:
The DISCUS package consists of four programs, each of which could be used independently or in combination. The first program in the package is DISCUS itself and the development started some 15 years ago by Reinhard Neder. DISCUS is a general program to generate disordered atomic structures and compute the corresponding experimental data such as single crystal diffuse scattering or the atomic pair distribution function (PDF). Features include symmetry operations, Monte Carlo simulation capabilities and the generation of domain structure to name just a few. More recently DISCUS developments include the simulation of nanoparticles.
http://www.lks.physik.uni-erlangen.de/diffuse_workshop/index.html