[Ifeffit] Constraining values in Artemis fit

Matt Newville newville at cars.uchicago.edu
Thu Aug 23 10:26:57 CDT 2018


On Thu, Aug 23, 2018 at 10:03 AM Thomas, Andrew (AGW) <andrew.thomas at kit.edu>

> Hello,
> Does anyone have any suggestions for breaking the correlation between the
> coordination number and sigma^2? Specifically, is there a way to set a
> maximum or minimum value for parameters in a fit?

Hmm, those seem like completely unrelated questions to me.   Do they seem
related to you?

Coordination number and sigma2 are highly correlated as both alter the
EXAFS amplitude.  That cannot be "broken".

You can set maximum and/or minimum values for parameters in a fit.  This is
much more robust in Larch than in Ifeffit, and is documented at

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