Powder Diffraction - Spallation Neutron Source

Limitations of Rietveld
Rietveld can only discern parameters that have effects on the
powder diffraction pattern
– Cannot separate some effects ever
• Absolute configuration
• Magnetic moment directions unless they break symmetry
If two parameters have approximately the same effect on the
powder diffraction pattern, they correlate and they cannot be
differentiated (e.g. occupancies & displacement parameters)
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