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-request@millenia.cars.aps.anl.gov

You can reach the person managing the list at
        ifeffit-owner@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: Energy Resolution (Julian Ehwald)
   2. Re: Energy Resolution (Robert Meulenberg)
   3. 4+2 model for distortion (Abdul Ahad)
   4. Re: 4+2 model for distortion (Anatoly Frenkel)


----------------------------------------------------------------------

Message: 1
Date: Wed, 9 May 2018 09:24:27 +0200
From: "Julian Ehwald" <jehwald@gmail.com>
To: "'Carlo Segre'" <segre@iit.edu>, "'XAFS Analysis using Ifeffit'"
        <ifeffit@millenia.cars.aps.anl.gov>
Subject: Re: [Ifeffit] Energy Resolution
Message-ID: <006901d3e766$c4284410$4c78cc30$@gmail.com>
Content-Type: text/plain;       charset="iso-8859-1"

Hi Carlo

Thank you very much for your answer! If you say it is sufficient to use
dk=0.05, that means I would be able to collect a full EXAFS spectra (k=0 to
12) in only 250 datapoints? That would save us a lot of time!

Best, Julian

-----Urspr?ngliche Nachricht-----
Von: Ifeffit [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] Im Auftrag
von Carlo Segre
Gesendet: Sonntag, 6. Mai 2018 01:07
An: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov>
Betreff: Re: [Ifeffit] Energy Resolution


Hi Julian:

With an edge energy of 543 eV, your monochromator resolution should be at
least 0.1 eV.  If you are interested in XANES, you need to take data at this
resolution or maybe even better.  ONce past the edge, there is no need to
keep that step size.  If your beamline permits an EXAFS-type step scan with
steps in k-space, you want to use a dk of 0.05 which is what IFEFFIT
interpolates to.  Smaller step sizes are not really useful.

Carlo

On Sat, 5 May 2018, Julian Ehwald wrote:

> Dear all,
>
>
>
> This might be a very general question, but: I was wondering what
> energy resolution you typically use at beamlines to obtain your raw data
for exafs.
> Since we have limited Beamtime only and other experiments that we want
> to carry out, I was wondering what kind of resolution is common. Or
> differently: Is it predictable what happens if I for example change
> from steps of 0.2eV to 0.4eV? We want to obtain spectra up to 500eV
> above Oxygen K, if that is of relevance.
>
> Best, Julian
>
>

--
Carlo U. Segre -- Duchossois Leadership Professor of Physics Interim Chair,
Department of Chemistry Director, Center for Synchrotron Radiation Research
and Instrumentation Illinois Institute of Technology
Voice: 312.567.3498            Fax: 312.567.3494
segre@iit.edu   http://phys.iit.edu/~segre   segre@debian.org
_______________________________________________
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




------------------------------

Message: 2
Date: Wed, 9 May 2018 08:54:31 -0400
From: Robert Meulenberg <robert.meulenberg@maine.edu>
To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov>
Subject: Re: [Ifeffit] Energy Resolution
Message-ID:
        <CANs+nr9N7MSiYB9UGRm-a0JGd-5U8BNjKO7YVgAkM=SoRKazHA@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Julian,

Keep in mind that to get to k=12, you will need to go out to ~1100 eV.  At
these energies, you will encounter just about every 1st row transition
metal L edge, and a handful of other M-edges for heavier elements.  So if
you have anything else in your sample, EXAFS will probably not be
possible.  That is usually why people don't try to do EXAFS analysis at the
soft x-ray energies.

Regards,

Rob




Robert W. Meulenberg
Associate Professor of Physics
Laboratory for Surface Science and Technology
Department of Physics and Astronomy
University of Maine
Orono, ME 04469
phone: 207-581-2245
email: robert.meulenberg@maine.edu

On Wed, May 9, 2018 at 3:24 AM, Julian Ehwald <jehwald@gmail.com> wrote:

> Hi Carlo
>
> Thank you very much for your answer! If you say it is sufficient to use
> dk=0.05, that means I would be able to collect a full EXAFS spectra (k=0 to
> 12) in only 250 datapoints? That would save us a lot of time!
>
> Best, Julian
>
> -----Urspr?ngliche Nachricht-----
> Von: Ifeffit [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov] Im Auftrag
> von Carlo Segre
> Gesendet: Sonntag, 6. Mai 2018 01:07
> An: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov>
> Betreff: Re: [Ifeffit] Energy Resolution
>
>
> Hi Julian:
>
> With an edge energy of 543 eV, your monochromator resolution should be at
> least 0.1 eV.  If you are interested in XANES, you need to take data at
> this
> resolution or maybe even better.  ONce past the edge, there is no need to
> keep that step size.  If your beamline permits an EXAFS-type step scan with
> steps in k-space, you want to use a dk of 0.05 which is what IFEFFIT
> interpolates to.  Smaller step sizes are not really useful.
>
> Carlo
>
> On Sat, 5 May 2018, Julian Ehwald wrote:
>
> > Dear all,
> >
> >
> >
> > This might be a very general question, but: I was wondering what
> > energy resolution you typically use at beamlines to obtain your raw data
> for exafs.
> > Since we have limited Beamtime only and other experiments that we want
> > to carry out, I was wondering what kind of resolution is common. Or
> > differently: Is it predictable what happens if I for example change
> > from steps of 0.2eV to 0.4eV? We want to obtain spectra up to 500eV
> > above Oxygen K, if that is of relevance.
> >
> > Best, Julian
> >
> >
>
> --
> Carlo U. Segre -- Duchossois Leadership Professor of Physics Interim Chair,
> Department of Chemistry Director, Center for Synchrotron Radiation Research
> and Instrumentation Illinois Institute of Technology
> Voice: 312.567.3498            Fax: 312.567.3494
> segre@iit.edu   http://phys.iit.edu/~segre   segre@debian.org
> _______________________________________________
> 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
>
>
> _______________________________________________
> 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
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20180509/41e10182/attachment-0001.html>

------------------------------

Message: 3
Date: Wed, 9 May 2018 20:11:24 +0530
From: Abdul Ahad <matrixabdulahad@gmail.com>
To: ifeffit@millenia.cars.aps.anl.gov
Subject: [Ifeffit] 4+2 model for distortion
Message-ID:
        <CAEFSGt6rZiDGp+sxbGQY_BgB8Oawu5_jzAyyAUkuZqn-HH74pQ@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

hi all
How to include this model in atom that is 4+2 or 2+4 for 2short or 4 long
bond length of octahedra
thanks


*A. Ahad*
*--------------------*
*Abdul Ahad*
Junior Research Fellow
*Dept of Physics*
*Aligarh Muslim University*
*Aligarh 202002 (U.P.), India*

*http://www.researcherid.com/rid/G-8198-2018
<http://www.researcherid.com/rid/G-8198-2018>*
*Email: a_ahad.rs@amu.ac.in <a_ahad.rs@amu.ac.in>, ahad@mailaps.org
<ahad@mailaps.org> *
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20180509/46512fd3/attachment-0001.html>

------------------------------

Message: 4
Date: Wed, 9 May 2018 11:00:08 -0400
From: Anatoly Frenkel <anatoly.frenkel@stonybrook.edu>
To: XAFS Analysis using Ifeffit <ifeffit@millenia.cars.aps.anl.gov>
Subject: Re: [Ifeffit] 4+2 model for distortion
Message-ID:
        <CAFsMoZam=Pu2hPKiF+oMU6uh5EbZc4ZY9VT=xADtEdoyyN=5pw@mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

Cute animation. I will now think of dynamic Jan Teller distortion every
time I see a flying pigeon.
Anatoly



On Wed, May 9, 2018 at 10:41 AM, Abdul Ahad <matrixabdulahad@gmail.com>
wrote:

> hi all
> How to include this model in atom that is 4+2 or 2+4 for 2short or 4 long
> bond length of octahedra
> thanks
>
>
> *A. Ahad*
> *--------------------*
> *Abdul Ahad*
> Junior Research Fellow
> *Dept of Physics*
> *Aligarh Muslim University*
> *Aligarh 202002 (U.P.), India*
>
> *http://www.researcherid.com/rid/G-8198-2018
> <http://www.researcherid.com/rid/G-8198-2018>*
> *Email: a_ahad.rs@amu.ac.in <a_ahad.rs@amu.ac.in>, ahad@mailaps.org
> <ahad@mailaps.org> *
>
> _______________________________________________
> 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
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20180509/5dca1a3e/attachment.html>

------------------------------

Subject: Digest Footer

_______________________________________________
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


------------------------------

End of Ifeffit Digest, Vol 183, Issue 9
***************************************