Dear Rietvelders I've a basic question on the Rietveld agreement index S (goodness of fit) . In "The Rietveld Method" (ed. R.A. Young) it says in chapter 1.4 "An S value of 1.3 or less is usually considered to be quite satisfactory. An S value of 1.7, for example, probably is a warning that you should look further into the reasons and question the adequacy of your model." In the literature, however, papers are published quite frequently with considerably larger S values (I'm just looking at an Acta Cryst. B paper with S values between 6 and 8.5).
The question is now how strict has the 1.3 limit to be applied, what is the "largest acceptable" S value? How does one assess S>1.7 and justify it to referees? I should add that I'm not a follower of the R-value cult but think that the most important criterion is chemical and physical plausibility. Thanks for your advice. Franz Werner -- Der GMX SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! Ideal für Modem und ISDN: http://www.gmx.net/de/go/smartsurfer
