[Ifeffit] SCF cards in EXAFS and SO2 of CO, Mn and Cu

Scott Calvin SCalvin at slc.edu
Sun Jan 18 08:44:52 CST 2009

In my experience SCF is only good for one thing in EXAFS: estimating  
the E0 shift. As long as that is a parameter that you are fitting, in  
my experience SCF is not necessary. It doesn't hurt, but it does take  
a lot of time to run FEFF when the card is included.

As far as S02 of those transition metals, it is best to run metal foil  
standards on the same beam line as your samples. One reason for this  
is that there are instrumental effects that can mimic changes in S02,  
and it's best to account for them. For instance, no monochromator is  
actually exactly monochromatic. The presence of other energies will  
act to reduce S02 to some extent, but the extent will vary from beam  
line to beam line, and often from run to run.

--Scott Calvin
Sarah Lawrence College

On Jan 18, 2009, at 12:31 AM, JeongEunSuk wrote:

> Hello everyone
> I am using FEFF8.0 for the analysis of EXAFS. In FEFF, SCF card is  
> for the calculation of self-consistent potential.
> I usually omitted SCF card for EXAFS. Is it right?
> Because the potential affects phase shift, I think that SCF card is  
> also used in the analysis of EXAFS.
>  which is correct, using SCF card or not  in EXAFS?
> and I have another requirement. Could I know SO2  of Co, Mn and Cu?
> If anyone know those, would you show me?

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