[Ifeffit] (no subject)
Scott Calvin
SCalvin at slc.edu
Thu Feb 15 06:59:25 CST 2007
Hi Ruwn,
Using a different S02 for each path effectively means that you're
using a different coordination number for each path. In some cases,
that may be appropriate--for example, small nanoparticles with
unknown morphology. It should be noted, however, that S02 often
correlates highly with sigma2, and a fit that prefers different S02's
may be getting "mixed up" with sigma2's...although in a case like
that Artemis/Ifeffit will give high uncertainties to the S02's it finds.
More fundamentally, just because a fit matches the data well, it
doesn't mean it's "good." The choice of parameters to fit must also
be physically justifiable. If you can justify each path having a
different coordination number than in your model, you can try
different S02's; otherwise, your fit is unconvincing.
--Scott Calvin
Sarah Lawrence College
At 02:31 AM 2/15/2007, you wrote:
>Dear Bruce
>
>
>
>We have used Athena and Artemis software to analyses the EXAFS. When
>we do the analysis, we used different S2o for each path for fitting
>of Cu2O data. I succeeded to obtain good fitting by this way.
>Documents related to percent EXAFS analysis have been mentioned S2o
>is one value for all paths. What I want to know is our fittings are
>correct or not. I am looking forward early response.
>
><?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />
>
>About 10 years ago we had being using another program made by
><?xml:namespace prefix = st1 ns =
>"urn:schemas-microsoft-com:office:smarttags" />Tokyo University in
>Japan. In this program, the refined parameters also included S2oj
>and Nj to the each cells
>
>
>
>Thanks
>
>
>
>Ruwn
>_______________________________________________
>Ifeffit mailing list
>Ifeffit at millenia.cars.aps.anl.gov
>http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
More information about the Ifeffit
mailing list