The Harwell TAILS computer program

The Harwell TAILS computer program is a versatile program for crystal structure refinement through the analysis of neutron or X-ray diffraction data from single crystals or powders. The main features of the program, which include the use of integrated intensities as the observed qualities, the ability to apply corrections for extinction and thermal diffuse scattering and the facility for modelling anharmonic thermal vibrations, are described. Examples of its application are also given.