Hi,
After the IUCr Monograph on Crystallography 13 (2002)
entitled "Stucture Determination from Powder Diffraction Data"
you may find in the preface :
"Although the Rietveld method of structure refinement from powder
diffraction data is often loosely considered to be synonymous with structure
determination, it is not. The Rietveld method only comes into play in the
final stage of the structure solution process when an approximate structural
model has been found."
WIF David, K Shankland, LB McCusker, C Baerlocher
A clear distinction having my complete agreement.
Armel
http://www.cristal.org/CAC-XX/maze.jpg
http://www.cristal.org/CAC-XX/Rietveld.ppt
> Message du 29/08/18 10:14
> De : "May, Frank"
> A : "Alan Hewat" , "rietveld_l@ill.fr"
> Copie à :
> Objet : RE: Rietveld website cancelled ?
>
> To all:
>
> Initially I sent this to Alan who suggested I open discussion to the entire
> community. I've posted similar in past years and have been FLAMED. Please
> keep it civil. ;-)
> =====================
> As a long time practitioner of powder XRD (since 1972) I was there when the
> superconductor craze hit in the mid-1980s. At that time it was recognized the
> Rietveld Method was useful only for REFINING structures which were generally
> accepted from single crystal x-ray analysis.
>
> The http://www.cristal.org/rietv025/ link says the method "[allows] an
> accurate determination of the structure." I take that statement to mean no
> model is required; Rietveld Analysis can determine structure without
> preconceived model.
>
> Thanks for reading.
>
> Blessings from toasty and warm St. Louis, MO.
>
> Frank May
> Research Investigator
> University of Missouri-St. Louis
>
> formerly at Monsanto Company (which recently became part of
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