The DISCUS package consists of four sections. The top section is a short rooftop to the three working sections DISCUS, DIFFEV, KUPLOT. The first section in the package is DISCUS itself and the development started some 30 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. DISCUS is the engine behind the new Nanoparticle Builder hosted by Los Alamos National Laboratory.

The second section is DIFFEV. This is a generic minimization program using an evolutionary algorithm. It is designed to work with the other programs in the package.

The third section is REFINE. This is a Least Squares based refinement section. It is designed to work with the other programs in the package.

Finally the package contains a general plotting section called KUPLOT.

Please note that the program PDFFIT has been retired. A completely rewritten version can be found at http://www.diffpy.org.

Thomas Proffen and Reinhard Neder