In *.sum file, I have looked for standard deviation. But two parameters are there: Deviance and Dev*. Are these the same thing as standard deviation. If yes, which one of these can be considered as the standard deviation. And what is the difference between Deviance and Dev*.
In *.sum file of my sample, these two have values: Deviance: 0.375E+04 Dev* : 1.123.
Dear Volker Kahlenberg
Thank you very much for your reply.
Yes sir, you are right. I used Fullprof package for the refinement.
I found a reference from the manual to understand deviance "A. Antoniadis, J. Berruyer & A. Filhol, Acta Cryst. A46, 692 (1990)".
Since, the Deviance is the deviation in the value of Chi2, therefore its value should be small. However, it is not so in my case.
All the values of agreement factors are small and fitting of pattern is also good. But the value of Deviance is large.
N-P+C: 3340
=> R-factors (not corrected for background) for Pattern: 1
=> Rp: 1.22 Rwp: 1.64 Rexp: 1.55 Chi2: 1.12 L.S. refinement
=> Conventional Rietveld R-factors for Pattern: 1
=> Rp: 20.2 Rwp: 10.5 Rexp: 9.96 Chi2: 1.12
=> Deviance: 0.375E+04 Dev* : 1.123
=> DW-Stat.: 1.0599 DW-exp: 1.9306
=> N-sigma of the GoF: 4.761
=> Global user-weigthed Chi2 (Bragg contrib.): 1.14
Is it okay to report these values of R-factors and Chi2, even though the value of Deviance is large. Or am I making some mistake and I should do the refinement again.
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