Hi Dien, When I look at your project, I find that I have to add Parameters to the GDS page for the "P1.1" path. When I include that in the fit, the coordination number for that Path goes to 0 (0.07 +/- 0.3) and that "ss_P11" is -0.03 +/- 0.04. Both "P1.1" and "P1.4" show values for "delr" that are above 0.8 Ang, pushing them both to be at R ~ 4.0 Ang.
My guess would be that those might not be the best paths to use here. It does look like there is something with R ~ 3.8 Ang, but I might I am not sure I can guess what that is... On Fri, Sep 9, 2022 at 11:32 AM dien...@srnl.doe.gov <dien...@srnl.doe.gov> wrote: > Hi, Matt and Carlo and other EXAFS experts > > > > Attached please find a fpj data file. The basic system is silica + PO4 > ligand on surfaces, which was used for adsorption of La. We collected La > L3-edge EAXFS data and did this fitting. I used two models of La binding as > monodentate and bidentate. I saw the negative ss parameter. I saw this in > some of my other EXAFS data fitting samples as well. I have two questions > for help: > > 1. What might cause the negative ss parameters and how I may improve > this, is this caused by incorrect structure models > 2. If we can do some “stress” test to make sure the fitting is valid > and meaningful. > > > > Please you can help look at and play this data set and direct me on how to > do this correctly, thank you so much. > > > > Dien Li > > Savannah River National Laboratory > > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit > --Matt
_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit Unsubscribe: http://millenia.cars.aps.anl.gov/mailman/options/ifeffit
