[Ifeffit] references

[Soma Chattopadhyay]

Thanks, Matt and Jason.
I very much appreciate the prompt replies from both of you.
best
Soma

Jason Gaudet wrote:
> Hi Soma!
>
> Google "S02 transferability site:http://millenia.cars.aps.anl.gov/" 
> and you'll find lots of messages on the subject if you haven't already.
>
> There's a post from Bruce on May 4 2010 where he writes:
>
> Recent work from John Rehr's group has elaborated on this,
> demonstrating that S02 is, in the strictest sense, neither
> transferable nor constant in energy.  However, these effects are small
> such that chemical transferability remains a useful and defensible
> practice in many EXAFS analyses.
>
> http://millenia.cars.aps.anl.gov/pipermail/ifeffit/2010-May/009378.html
>
> I don't know what specific work he's referring to but that might be a 
> good direction.
>
> -Jason
>
> On Tue, Jan 22, 2013 at 1:15 PM, Matt Newville 
> <newville at cars.uchicago.edu <mailto:newville at cars.uchicago.edu>> wrote:
>
>     Hi Soma,
>
>     On Tue, Jan 22, 2013 at 11:11 AM, Soma Chattopadhyay
>     <soma at agni.phys.iit.edu <mailto:soma at agni.phys.iit.edu>> wrote:
>     >
>
>     > 2) A lot of times we find So2 from the respective metal  foil
>     and fix it
>     > when we fit the sample data for the same element. Is there any
>     reference for
>     > this one?
>     >
>     > I know about the book by Shelly, Hesterberg and Ravel.
>     > Would appreciate if I get some more references.
>
>     I'm not aware of a truly thorough study of this convention. Several of
>     the early UWXAFS papers mention using this approach.  Probably the
>     clearest statement is from
>
>       E A Stern, et al "The UWXAFS Analysis Package - Philosophy and
>     Details",
>       Physica B208  pp 117-120  (1995)
>       [DOI: 10.1016/0921-4526(94)00826-H]
>
>     which states (full paragraph):
>
>         The set of parameters that most frequently have a strong
>         enough correlation to give difficulty in obtaining their
>         values separately are S02, the passive electron overlap
>         constant[13], sigma^2, the disorder about the optimal
>         distance, and N, the number of atoms in a particular
>         coordination shell. The most reliable way to separate out
>         sigma^2 from the other two parameters is to measure the
>         temperature dependence of sigma^2 and vary the product S02*N
>         so as to obtain a fit to an Einstein oscillator, particularly
>         the zero point value. Since S02 is dependent essentially on
>         only the center atom, it can be found in known structures and
>         N determined from the S02*N value.
>
>     Here Reference 13 is to Stern and Heald's chapter in the Handbook of
>     Synchrotron Radiation Vol 1 (1983).
>
>     Cheers,
>
>     --Matt
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