Profile-fitting of single crystal diffraction data

Profile-fitting methods have received great attention in the area of structure analysis from powder diffraction data. Although the use of profile fitting for the reliable extraction of integrated intensities from single-crystal diffraction data has long been proposed in the literature, a limited number of applications and tests of the method have been performed on single-crystal X-ray or neutron diffraction profiles. The profile-fitting technique is here employed to extract integrated intensities from two troublesome data sets of single-crystal diffraction profiles, one affected by multiple scattering effects (X-ray) and the other showing scan truncation (neutrons). It is shown that die proposed implementation of the profile-fitting procedure has great advantages in producing reliable integrated intensities compared with conventional integration methods. Furthermore, during die data processing, any anomalous diffraction profile is easily detected and proper analysis of instrumental background and scan-truncation effects is performed. The method thus allows effective evaluation of the quality of the treated data set. It is proposed that the profile-fitting technique for the extraction of single-crystal integrated intensities be used routinely when diffraction data of superior quality are needed for crystal structure analysis.