Abstract The Monte Carlo program CATCH (Capture And Transport of CHarged particles in a crystal) for the simulation of planar channelling in bent crystals is presented. The program tracks a charged particle through the distorted-crystal lattice with the use of continuous-potential approximation and the non-diffusion approach to the processes of scattering on electrons and nuclei. The output consists of the exit angular distributions, the energy loss spectra, and the spectra of any close-encounter process of interest. The curvature variability, face twist, and various surface imperfections of the real crystal can be taken into account.
