Hello Yanny:
I've modeled a few Pt EXAFS spectra and have found that using an E0 at the top
of the white line usually does a better job of getting the data close to the
theory. This seems to be often the case with the L3-edges as they are rather
broad compared to the K-edges of transition
Hello Fellow XAS scientists:
We have a position open for beamline scientist in the Spectroscopy Group at the
APS. Please reach out to all those that might be interested in joining our team
here in Chicago-land area.
Hello Joyti,
I'm not sure I know what your definition of 'exact' and 'average'. The exafs
signal comes from each atom that is probed by the x-ray beam. The total signal
is exactly an average of the local atomic environment of all atoms. If half
the atoms have 4 carbon neighbors and the other
Hello Harry:
I’m not sure how to help you with your specific question, but you might find
this paper helpful.
High Energy Resolution Fluorescence Detection of the Pt L3, 2-Edge Whitelines
of Pt-Based Bimetallic Systems: Implications for the Pt 5d5/2, 3/2 Density of
States
Chen J, Finfrock Y,
Hi Will:
The relationship between the data in k-space and R-space is described in this
tutorial:
https://docs.xrayabsorption.org/tutorials/Basics_of_XAFS_to_chi_2009.pdf
Take a look at what a Fourier transform does. In few words I'd say it doesn't
matter which representation of the data
Hi Peng:
It might be helpful to understanding some of Matt's points regarding S02
transferability, Ei and energy resolution by looking at this paper.
Comparison of EXAFS foil spectra from around the world
DOI: 10.1088/1742-6596/190/1/012032
Kind regards,
Shelly
-Original Message-
Hello XAFS community:
I'm excited to let you know that we have an opening for beamline scientist
within the Spectroscopy group at the Advanced Photon Source. Please help spread
the word.
https://bit.ly/3iN7Ehe
Kind Regards,
Shelly Kelly
Spectroscopy Group Leader
Advanced Photon Source
Hi Lisa,
Be sure that Athena has been rigorously tested and she does know how to
normalize data. It is much more likely that the default values are not
the best ones for your data.
My book chapter goes over how Athena normalizes data in detail. If you
send me your email address I'll send you a
I believe the problem is a comment line that contains a single number.
If you remove that line, they read in just fine.
Shelly
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-
boun...@millenia.cars.aps.anl.gov] On Behalf Of Christopher Allen
Sent:
Hi Damdin,
I apologize for not getting a response to you sooner. It is possible to both
of the things that you suggest.
In the future, it would be helpful to use a good subject line for your
question.
Cheers,
Shelly
-Original Message-
From:
Hi Eug,
I'm not sure that I understand your question. Do you mean that your ran FEFF
and want to plot the magnitude of the Fourier transform of the FEFF
calculation? If so, you will want to use Artemis for that. There is
information about how to use Artemis on the tutorials page of
and what we are trying to say is that your method is not generally
accepted as the best way to model data.
Shelly
From: ifeffit-boun...@millenia.cars.aps.anl.gov
[mailto:ifeffit-boun...@millenia.cars.aps.anl.gov] On Behalf Of abhijeet
gaur
Sent:
Okay. Sure, I agree with Matt. But I don't think that this data can be
broken into different shellsotherwise I do not believe that the
model would fail when the entire data range is optimized together.
There could be two reasons that the model fails. Either there are
correlations that were
Hi Haiyan,
Please send me mail directly to get a copy of the book chapter.
dr.sdke...@gmail.com
Cheers,
Shelly
From: ifeffit-boun...@millenia.cars.aps.anl.gov
[mailto:ifeffit-boun...@millenia.cars.aps.anl.gov] On Behalf Of haiyan
Sent: Tuesday,
Hi Guven,
Wow that is amazing. Would you share your Athena project file with us?
I believe that it is possible but I'm a bit surprised that the numbers
flip so evenly. What happens when you increase the energy range on the
xanes fit so that it includes more of the EXAFS features? And what
Hi Andy,
I have a book chapter that details how to set the k-range for a data
set. It also talks about Rbkg in detail. If you want a copy just send
me an email.
Cheers,
Shelly
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-
Hi Damdin,
S02 is 100% the same as the CN, the degeneracy, and the edge step
determined in the background removal process. Your S02 is a bit on the
small side so I would check the edge step in Athena. I would also check
the CN used in the model by looking at the results page for each path.
This
: [Ifeffit] Request for Foil Spectra
Dear Shelly,
I have spectra of Au and Cu foils recorded at ambient conditions at
the
ESRF.
Do you want them?
Gleb
Kelly, Shelly wrote:
!-- /* Font Definitions */ @font-face {font-family:SimSun;
panose-1:2
1 6 0 3 1 1 1 1 1;} @font-face {font
Hi Everyone,
I'm planning on submitting a small EXAFS 14 paper on the comparison of
S02 from different beamlines using foils of Cu, Pd, Ag, and Au spectra.
I've raided the APS/XOR data for Cu and Ag spectra from all around the
APS ring. If you would like to donate foil spectra to the cause,
Thanks for all the kind words. We hoped the chapter would be useful.
Cheers,
Shelly
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov on behalf of Dominik Samuelis
Sent: Fri 1/16/2009 5:52 AM
To: lnch...@yahoo.co.uk; XAFS Analysis using Ifeffit
Subject: Re: [Ifeffit]
Oh drat. I didn't realize that this went to the whole list. Sorry for
filling up your email box.
Shelly
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-
boun...@millenia.cars.aps.anl.gov] On Behalf Of Kelly, Shelly
Sent: Thursday, January 15
Hi Hashem,
I show one method for doing this in my book chapter Figure 14-23 on page 431.
(I feel a bit like a broken record). I will send you a copy if you want.
Shelly
-Original Message-
From: ifeffit-boun...@millenia.cars.aps.anl.gov [mailto:ifeffit-
Hi Bindu,
There are lots of descriptions of these concepts on the exafs.org web page.
Check out the Tutorials page.
I wrote about them in my book chapter on page 58. If you like, I can send you a
copy. It is kinda big so you will need to have 8Meg space in your mail box.
Shelly
-Original
Hi Ruoshuang,
Go to the settings menu - Plugin Registry and then check the X10C read
files from NSLS beamline X10C button. And then try again.
Shelly
-Original Message-
From: [EMAIL PROTECTED] [mailto:ifeffit-
[EMAIL PROTECTED] On Behalf Of Ruoshuang Huang
Sent: Monday, November
Hi Jens,
Here is my stab at pitching in.
The x-ray fluorescence signal is a sum of the signals from all the N
atoms in the sample that are in the x-ray beam. (Assume that the sample
is not too thick so that all the fluorescent x-rays can get out of the
sample.) The background slope of the
Hi Guvenc,
It sounds like you need to build some basics. A great place to start is
with the Athena and Artemis documentation and the tutorials on
www.xafs.org.
There are also worked examples using Artemis and Athena installed with
the software. Ifeffit\examples\Artemis\ZnO might be an
?
Or instead do you mean that an inappropriate choice of standards can
create unreliability in the fit? I would appreciate any details you can
add to your repsonse.
Thanks,
Don
On Thu, 2008-02-10 at 14:22 -0700, Kelly, Shelly wrote:
Hi Andrew,
If you are fitting XANES spectra
Hi Mauro,
If I understand correctly, you would like to generate a feff.inp file from an
atoms.inp file where the only Fe atom is the absorber. But the resulting
feff.inp file can not be run because it always makes an ipot 1 for a
neighboring Fe atom but there are not any. So you have to go in
I'd like to add my 2cents worth about the mean square displacement term. I
wrote it up on the EXAFS wiki, since I like to say it over and over. see
http://www.xafs.org/Common_Mistakes
Shelly
From: [EMAIL PROTECTED] on behalf of Scott Calvin
Sent: Wed
Hi Eckhard,
The first slide also has problems. The first path is a single scattering path.
All the others are double scattering paths. The word single, double and
triple are used to describe the number of atoms that scatter. The number of
legs is used to tell the difference between the
Yah know,,,I'm wrong The last one is a triple scattering path with just two
scattering atoms. the leg part is right...
oops
SK
From: [EMAIL PROTECTED] on behalf of Kelly, Shelly D.
Sent: Wed 7/16/2008 11:45 PM
To: XAFS Analysis using Ifeffit
Subject: Re
Hi Joseph,
I have a book chapter that explains how the different k-weighting affect
the chi(k) data produced in the background removal. I'll send it to you
directly, so as not to fill up everyone's mail box.
Here is the reference for others that might be interested.
Kelly, S.D., Hesterberg,
Hi Lachlan,
The reason that you want to keep the total absorption less than 3 is because
the number of transmitted x-rays becomes small. I=I0 exp(-mu x). So for mu x
=3 the number of transmitted x-rays are 5% of the incident x-ray intensity. If
you have a lot of x-rays then you can
Hi Fenglong,
You can do the next part of the analysis in Artemis. I have a powerpoint
tutorial showing the different parts of Artemis on the xafs.org wiki.
http://www.xafs.org/Tutorials
It is called Basics_of_XAFS_analysis.pdf It is a bit dated now, but the main
points are all the same.
I
Hi Eckard,
I realize that you have posted a message every month for about 3 months
in a row without any reply: Shame on us... I will try to answer some of
your questions and maybe that will help to get some discussion going.
The energy scale in feff8 is NOT defined as you would expect it to
Hi Tony,
The approach that I like to take, is to vary the choice of E0 in the
background subtraction step so that the chi(k) spectra are well aligned
with each other and the theory. Then only one Ezero parameter is
needed.
Cheers,
Shelly
-Original Message-
From: [EMAIL PROTECTED]
Hi Scott,
The change in frequency is a bigger affect at high k than the energy
shift parameter. The energy shift parameter affects the data more
strongly at low k. So I align the data to each other at low k, and then
they become out of phase with each other at high k. A similar effect is
seen
Hi Jens,
I believe the problem is related to the structure in the data before E0.
If you choose e0 to be at the beginning of the structure then the
normalization is handled better by Athena. Take a look at the attached
project file. The first data set with e0 on the edge as you would
choose for
and do not use any E-shift.
Bruce or Matt may have to comment, but it appears to me that the
normalization/flatten routine may not be dealing with the E-shift
appropriately.
Dave
-Original Message-
From: [EMAIL PROTECTED]
[mailto:[EMAIL PROTECTED] On Behalf
Of Kelly, Shelly D
Hi Todd,
One thing to try is to set s02 to a positive value and all the other
variables to reasonable values and then look at the real or imaginary
parts of the Fourier transform and also look at the chi(k) spectra. You
should see the affect that Scott mentioned.
Shelly
-Original
---
Shelly Kelly
Argonne National Laboratory
Bldg 203, RM E113
On Saturday 06 January 2007 10:53, Kelly, Shelly D. wrote:
Hello Artemis users,
I found an interesting feature in Artemis when generating a list of
atoms
from the attached cif file worth sharing
Hello Artemis users,
I found an interesting feature in Artemis when generating a list of atoms from
the attached cif file worth sharing on the list. In the attached cif file for
Pd2Si the position of the Si2 atoms are at x,y,z = 0., 0.6667, 0 with a
space group of p -6 2 m. Using this cif
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