(a) Diffraction spots on the detector area collected in a 360° spin of the sample around the diffraction vector of reflection . Sample–detector distance is 74.7 mm. X-rays of 10 keV, σ polarization. (b) Indexing of diffraction spots by simulation of the rotating crystal method [using the simulation routine in Appendix B of Morelhão (2016)]. Area detector width in horizontal direction.