[Ifeffit] Can the degeneracy (N) in Artemis be a variable?

[Scott Calvin]

I can't come up with a properly humble non-self-promoting way to say this, but for common fitting issues like this I'd cite my textbook. In my experience, I found it difficult to find good discussions of this kind of thing in the peer-reviewed literature, because they're either considered common knowledge or technical detail.

S. Calvin, XAFS for Everyone (CRC Press, 2013). 

The degeneracy S02 correlation issue is most directly discussed in Section 10.1.2.

--Scott Calvin
Sarah Lawrence College

On Jul 28, 2014, at 9:51 AM, Bruce Ravel <bravel at bnl.gov> wrote:

> 
> 
> Peng's question is so common on our mailing list that I would like to
> write a section of the Artemis document addressing it.
> 
> At heart, there are two issues.  The more important is that N is very
> highly correlated with S02 (and other things!).  The operational issue
> is the choice I made about only allowing numbers in the N box in
> Artemis.
> 
> I would like some suggestions for literature references on the more
> important part of this question.  Specifically, I'd like to know what
> references all of you cite on the topics of this high correlation and
> of solving the problem for real measurements.
> 
> With this bounty, I'll write up a section of the document which we can
> use when this question comes up in the future.
> 
> Thanks,
> B
> 
> 
> On 07/26/2014 12:56 PM, Peng Liu wrote:
>> Hi all,
>> 
>> When I model a standard, I know the degeneracy through the other data.
>> But for spectra of unknown material, I would like to set degeneracy as a
>> variable like the amplitude, deltE0, e.g.. However, I can assign a
>> letter to N and define it. Do you have any idea how I should do it?
>> 
>> Thanks for your reply,
>> 
>> Peng
>>