Hi Dominik, Thank you so much for your quick response. Indeed, it's really nice fitting according to your result. But my situation seems a little bit different as I'm dealing with the Mn XANES data and there're doublets and sometimes triplets in the pre-edge. Actually, I might as well explain my interest of doing such fitting. I read in the paper *(F Farges, PHYSICAL REVIEW B 71, 155109 (2005))* that the centroid of pre-edge peak is a more accurate measurement of the oxidation state of the element of interest, compared to the more conventional inflection point or half-way method. So I was trying to follow the paper and see if it also works for my samples. Anyway, thanks again for your help!
Enyuan On Thu, Aug 9, 2012 at 9:11 AM, <ifeffit-requ...@millenia.cars.aps.anl.gov>wrote: > Send Ifeffit mailing list submissions to > ifeffit@millenia.cars.aps.anl.gov > > To subscribe or unsubscribe via the World Wide Web, visit > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > or, via email, send a message with subject or body 'help' to > ifeffit-requ...@millenia.cars.aps.anl.gov > > You can reach the person managing the list at > ifeffit-ow...@millenia.cars.aps.anl.gov > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Ifeffit digest..." > > > Today's Topics: > > 1. Re: question for ifeffit mailing list - ATHENA NORMALIZATION > (Marie Zwetsloot) > 2. Re: question for ifeffit mailing list - ATHENA NORMALIZATION > (Scott Calvin) > 3. pre-edge centroid (Enyuan Hu) > 4. Re: pre-edge centroid (Dominik Samuelis) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Wed, 8 Aug 2012 13:17:59 -0400 > From: Marie Zwetsloot <mj...@cornell.edu> > To: ifeffit@millenia.cars.aps.anl.gov > Subject: Re: [Ifeffit] question for ifeffit mailing list - ATHENA > NORMALIZATION > Message-ID: > <CALtZdD54= > 1-w4u3vk7ddnu_cukgpk-1vj3ioor_csvkj4ue...@mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > Hi Scott Calvin, > > Thanks for your help. Yes, this is as far as my pre- and post-edge range > go. I realized I should have made them longer; it was my first time doing > this and wasnt aware that i should lengthen my pre and post-edge for later > on analysis. This will be good lesson for the future. > > So you would not recommend doing linear combination fitting? I was planning > on trying it out.. But I wouldnt want to do it if with my pre- and > post-edge range, I am bound to derive wrong conclusions from the data. > > Best, > Marie > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20120808/819dffdb/attachment-0001.htm > > > > ------------------------------ > > Message: 2 > Date: Wed, 8 Aug 2012 15:10:16 -0400 > From: Scott Calvin <scal...@sarahlawrence.edu> > To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > Subject: Re: [Ifeffit] question for ifeffit mailing list - ATHENA > NORMALIZATION > Message-ID: <b36e3403-35bc-48be-8e4d-ae2cb8556...@slc.edu> > Content-Type: text/plain; charset="iso-8859-1" > > Hi Marie, > > I think you can try linear combination fitting, but you'll have to build > in the uncertainty in normalization in to your own estimates of uncertainty. > > If you don't check the box that says "force weights to sum to 1," then you > can allow for normalization errors in your sample. > > If your standards also have only short energy ranges, then there's nothing > you can do about that, though. As I said, you'll just have to build them in > to your uncertainty. If you are unsure of the edge jump of a standard to > 20%, then the contribution of that standard to the linear combination fit > is uncertain by 20%. > > Uncertainty in normalization is one of the leading contributions to the > uncertainty that should be associated with linear combination fitting, even > when the energy ranges are sufficient. In a case like yours, they're bigger > than they could have been, but it doesn't mean you can't use linear > combination analysis at all. > > --Scott Calvin > Sarah Lawrence College > > On Aug 8, 2012, at 1:17 PM, Marie Zwetsloot wrote: > > > Hi Scott Calvin, > > > > Thanks for your help. Yes, this is as far as my pre- and post-edge range > go. I realized I should have made them longer; it was my first time doing > this and wasnt aware that i should lengthen my pre and post-edge for later > on analysis. This will be good lesson for the future. > > > > So you would not recommend doing linear combination fitting? I was > planning on trying it out.. But I wouldnt want to do it if with my pre- and > post-edge range, I am bound to derive wrong conclusions from the data. > > > > Best, > > Marie > > _______________________________________________ > > Ifeffit mailing list > > Ifeffit@millenia.cars.aps.anl.gov > > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > > > ------------------------------ > > Message: 3 > Date: Thu, 9 Aug 2012 00:21:14 -0400 > From: Enyuan Hu <bearcha...@gmail.com> > To: ifeffit <ifeffit@millenia.cars.aps.anl.gov> > Subject: [Ifeffit] pre-edge centroid > Message-ID: > <CAJud35NRYb67J7xLATPHPJGjEyvOK_gUKZur+dL9T30x8k= > u...@mail.gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > Dear all, > > I was wondering if anyone could comment on how to get the centroid of > pre-edge by fitting the pre-edge peak by pseudo-Voigt functions. I tried to > do that in Athena, but it seemed that peaking fitting part is the > relatively less developed function in the software. Any comment would be > appreciated. > > Enyuan > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20120809/3a09d07c/attachment-0001.htm > > > > ------------------------------ > > Message: 4 > Date: Thu, 09 Aug 2012 15:11:31 +0200 > From: Dominik Samuelis <d.samue...@fkf.mpg.de> > To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov> > Subject: Re: [Ifeffit] pre-edge centroid > Message-ID: <5023b703.6020...@fkf.mpg.de> > Content-Type: text/plain; charset="iso-8859-1"; Format="flowed" > > Dear Enyuan, > > in my experience, peak fitting works very well with Athena. Try not to > fit only the prepeak, but maybe include an arctan describing the edge > (see attached pdf, the fit was made using athena). This makes isolating > the prepeak much more reliable. > > Best regards, > Dominik > > On 09.08.2012 06:21, Enyuan Hu wrote: > > Dear all, > > > > I was wondering if anyone could comment on how to get the centroid of > > pre-edge by fitting the pre-edge peak by pseudo-Voigt functions. I tried > > to do that in Athena, but it seemed that peaking fitting part is the > > relatively less developed function in the software. Any comment would be > > appreciated. > > > > Enyuan > > > > > > _______________________________________________ > > Ifeffit mailing list > > Ifeffit@millenia.cars.aps.anl.gov > > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > > > -- > Dr. Dominik Samuelis > d.samue...@fkf.mpg.de > Max-Planck-Institut f?r Festk?rperforschung > Max Planck Institute for Solid State Research > Heisenbergstr. 1 > 70569 Stuttgart > Germany > Phone +49-711-689-1769 > Fax +49-711-689-1722 > Web http://www.fkf.mpg.de/maier/ > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: prepeak_fit.pdf > Type: application/pdf > Size: 108409 bytes > Desc: not available > URL: < > http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20120809/83335ed8/attachment.pdf > > > -------------- next part -------------- > A non-text attachment was scrubbed... > Name: smime.p7s > Type: application/pkcs7-signature > Size: 4534 bytes > Desc: S/MIME Cryptographic Signature > URL: < > http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20120809/83335ed8/attachment.p7s > > > > ------------------------------ > > _______________________________________________ > Ifeffit mailing list > Ifeffit@millenia.cars.aps.anl.gov > http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit > > > End of Ifeffit Digest, Vol 114, Issue 5 > *************************************** >
_______________________________________________ Ifeffit mailing list Ifeffit@millenia.cars.aps.anl.gov http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
