@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] sigma^2 values for multiple scattering paths
(Scott Calvin); Re: Ifeffit Digest, Vol 92, Issue 4
Message-ID: bc995ec7-578e-4256-9d62-de5e73831...@lbl.gov
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Hello Scott,
Just to make sure I understand what you mean
Not at all unusual, Han Sen. If you think about the EXAFS equation,
you'll see that sigma^2 and amplitude primarily affect the amplitude
of the signal, while distances affect the position of the peak in the
Fourier transform (or equivalently, the spacing of peaks in chi(k)).
So sigma^2 and
Hi Han Sen:
I agree that the small sigma2 values for the MS paths is suspect. The
data is saying that it wants more amplitude from these paths than is
physically possible. One way to increase the amplitude of the paths is
to make the scattering angle closer to 180deg for a linear path. It
is a
On Wednesday 06 October 2010 01:26:55 am Han Sen Soo wrote:
Hello,
I briefly read through the FAQ about this but I'm not sure if it answers my
question. Are there situations where the sigma^2 for a multiple scattering
path can be smaller than the direct paths? So small that they're on the
--
Message: 4
Date: Wed, 6 Oct 2010 09:02:21 -0500
From: Shelly Kelly dr.sdke...@gmail.com
To: XAFS Analysis using Ifeffit ifeffit@millenia.cars.aps.anl.gov
Subject: Re: [Ifeffit] sigma^2 values for multiple scattering paths
Message-ID
Although I agree with the main points that Bruce makes, I do want to
comment on one piece:
On Oct 6, 2010, at 7:03 AM, Bruce Ravel wrote:
.
In no case can I understand a physical explanation for the the MS
sigma^2 being smaller than for the SS.
Actually, there is a physical situation
)
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Message: 1
Date: Wed, 6 Oct 2010 09:39:49 -0700
From: Scott Calvin dr.scott.cal...@gmail.com
To: XAFS Analysis using Ifeffit ifeffit@millenia.cars.aps.anl.gov
Cc: dr.scott.cal...@gmail.com dr.scott.cal...@gmail.com
Subject: Re: [Ifeffit] sigma^2
On Oct 6, 2010, at 10:41 AM, Han Sen Soo wrote:
Hello Scott,
Just to make sure I understand what you mean, are you saying that in
your 3 atom system, the S1 and S2 atoms have relatively fixed
locations but A may have large vibrational amplitudes in the A-S1
and A-S2 directions? So the
