It is because you made delta E0=0, but the fit gave you delta E0=8. Since the
fit agrees with the data in k-space at low wavenumbers (I assume), then the
signal with delta E0=0 should not, and vice versa.
Anatoly
________________________________
From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Elsa Sileo
Sent: Thu 9/30/2010 11:33 AM
To: ifeffit@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] Ifeffit Digest, Vol 91, Issue 28
Dear Matt,
I have to perform EXAFS analysis, and when I tried to fit the first shell, I
found deltaE0 values of about 8 eV. Following the paper of Kelly et al
(Analysis of soils and minerals using X-ray absorption spectroscopy. In Methods
of soil analysis, Part 5: Mineralogical methods; 2008; pp 446) I fitted the
first shell obtaining values for deltaE0, sigma^2; delta R and amplitude. Then,
using the obtained values, and making deltaE0=0, I got the theoretical signal.
When I compare the experimental and theoretical spectrum I see a mismatch
between the position of the nodes at low wavenumbers.
Having done this, how I have to proceed to correct the experimental data in
order to obtain smalller delta E0 values?
Thanks in advance,
Elsa
--- El mié, 29/9/10, ifeffit-requ...@millenia.cars.aps.anl.gov
<ifeffit-requ...@millenia.cars.aps.anl.gov> escribió:
De: ifeffit-requ...@millenia.cars.aps.anl.gov
<ifeffit-requ...@millenia.cars.aps.anl.gov>
Asunto: Ifeffit Digest, Vol 91, Issue 28
Para: ifeffit@millenia.cars.aps.anl.gov
Fecha: miércoles, 29 de septiembre, 2010 14:00
Send Ifeffit mailing list submissions to
ifeffit@millenia.cars.aps.anl.gov
<http://es.mc278.mail.yahoo.com/mc/compose?to=ifef...@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
<http://es.mc278.mail.yahoo.com/mc/compose?to=ifeffit-requ...@millenia.cars.aps.anl.gov>
You can reach the person managing the list at
ifeffit-ow...@millenia.cars.aps.anl.gov
<http://es.mc278.mail.yahoo.com/mc/compose?to=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: Aligning Energy scales (Matt Newville)
----------------------------------------------------------------------
Message: 1
Date: Tue, 28 Sep 2010 12:55:15 -0500
From: Matt Newville <newvi...@cars.uchicago.edu
<http://es.mc278.mail.yahoo.com/mc/compose?to=newvi...@cars.uchicago.edu> >
To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov
<http://es.mc278.mail.yahoo.com/mc/compose?to=ifef...@millenia.cars.aps.anl.gov>
>
Subject: Re: [Ifeffit] Aligning Energy scales
Message-ID:
<aanlktima_bgt5oo=k-vb-0argwb9ac_w6bcblwgca...@mail.gmail.com
<http://es.mc278.mail.yahoo.com/mc/compose?to=k-vb-0argwb9ac_w6bcblwgca...@mail.gmail.com>
>
Content-Type: text/plain; charset=ISO-8859-1
Dear Elsa,
It sounds like you want to adjust the data chi(k) so that deltaE0 is 0
in a fit. Is that correct, or are you trying to do something else
(say, align the XANES)? If that assumption is correct, you want to
change the E0 used to extract chi(k) from the experimental spectra --
the E0 of the background subtraction. That is what sets k for the
data.
If that's not clear or not the right question, let us know,
--Matt
On Mon, Sep 27, 2010 at 2:00 PM, Elsa E. Sileo <si...@qi.fcen.uba.ar
<http://es.mc278.mail.yahoo.com/mc/compose?to=si...@qi.fcen.uba.ar> > wrote:
> I need to align a measured spectra to a theoretically calculated
spectra.
> I fitted the first shell obtaining values for deltaE0, sigma^2; delta
R and
> amplitude.
> Then, using the obtained values, and making deltaE0=0, I got the
theoretical
> signal.
> But I do not know how to use this last theoretical fit to align the
spectra.
> Can somebody help me?
>
> Thanks,
>
> Elsa
>
>
> Dra. Elsa E. Sileo
> Solidos Inorganicos
> INQUIMAE - Dto. Qca. Inorganica, Analitica y Qca. Fisica; FCEN, UBA
> Int. G?iraldes 2160, Pabell?n 2, Piso 3, Ciudad Universitaria -
C1428EHA
> CABA - Argentina
> Tel: (54 11) 4576 3380 ext. 113
> Fax: (54 11) 4576 3341
> e-mail: si...@qi.fcen.uba.ar
<http://es.mc278.mail.yahoo.com/mc/compose?to=si...@qi.fcen.uba.ar>
>
>
>
>
> _______________________________________________
> Ifeffit mailing list
> Ifeffit@millenia.cars.aps.anl.gov
<http://es.mc278.mail.yahoo.com/mc/compose?to=ifef...@millenia.cars.aps.anl.gov>
> http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
>
>
------------------------------
_______________________________________________
Ifeffit mailing list
Ifeffit@millenia.cars.aps.anl.gov
<http://es.mc278.mail.yahoo.com/mc/compose?to=ifef...@millenia.cars.aps.anl.gov>
http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
End of Ifeffit Digest, Vol 91, Issue 28
***************************************
ns
_______________________________________________
Ifeffit mailing list
Ifeffit@millenia.cars.aps.anl.gov
http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit
