Hi,

Does it make physical sense? No. You should be able to fit a known 
reference first shell,
or shells if there is more than one under the first peak in the 
transform (i.e. bcc has 2 plus
a bit of multiple scattering).

Check your data. Check how you processed your data. Compare with 
literature. Check
your Feff model.

Fitting the first shell(s) should give a reasonable So^2 estimate if the 
environments are similar
between reference and unknowns.

-R.

On 2025-02-12 4:38 a.m., avijay--- via Ifeffit wrote:
> Hello all,
>
> I am trying to fit my data using Artemis for a reference foil sample. However, the fit seems to get worse when I include the scattering paths at lowest R (i.e. the first shell scattering, with the highest rank). Does it make physical sense to not include this in the fitting? Is it acceptable to try and fit only a certain range of the |X(R)| vs R for the foil reference - in order to estimate the amplitude reduction factor for subsequent fitting of the real samples?
>
> Any insight/advice is much appreciated. Thank you.
>
> Best,
> A
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