DIFFRAC.SUITE TOPAS is the latest generation Rietveld software. The basics of the Rietveld method were published in the late 1960´s, when the Dutch crystallographer Hugo Rietveld presented computer based analytical procedures making use of a complete powder diffraction pattern recorded with neutrons.
Basically, the Rietveld method is using analytical profile functions and least-squares algorithms to fit a theoretical to a measured pattern.
Rietveld’s work opened the path to extract detailed crystal structure information from powder diffraction using neutron and X-ray data. These days, the Rietveld method is not only used for structure analysis, but also for the quantification of multi-phase mixtures and the determination of the crystallite microstructure which covers size and strain.