DISCO: a general software tool for dislocation contrast factor calculations in diffraction analysis

Dislocation contrast factors (CFs) play a central role in diffraction-based analyses of plastic deformation, linking the elastic strain fields generated by dislocations to diffraction line broadening. Despite their importance, the calculation of CFs remains a non-trivial task for low-symmetry crystal structures or arbitrary slip systems and is often limited to pre-tabulated solutions for selected lattice types. In this work we present DISCO, a software package for the real-time computation of dislocation contrast factors for any crystal structure and slip system. DISCO supports all space groups, from cubic to triclinic, and allows the calculation of CFs for individual crystallographic directions, as well as orientation-averaged CFs suitable for randomly oriented powder and polycrystalline diffraction analyses. The design principles, computational workflow and input/output structure of DISCO are described in detail, and its capabilities are illustrated through application examples on (cubic) SrTiO₃, (hexagonal) 4H-SiC and (monoclinic) β-Ga₂O₃.