The Advanced Photon Source
a U.S. Department of Energy Office of Science User Facility

Judging quality: Catching common refinement problems

Presentation Goal
  • Discuss how to find problems in Rietveld fits. This talk explores the weakness of R-factors and the importance of looking at plots of the observed and computed patterns.
  • Format: PDF slides or a RealPlayer video of the slides with accompanying audio.
Presentation Outline
  • What are [some of] the Rietveld R-factors and what do they measure
  • Graphical analysis of Rietveld fits
    • Background problems
    • Unindexed peaks (lowered symmetry or 2nd phase?)
    • Poor fit of peak shapes
    • Refereeing: using & plotting fits from CIF