[GSAS-II] Unable to fit any parameters of peaks in v 2644

[Ari Gold-Parker]

Hello,

I am attempting to do a structural refinement of standard powder XRD data.
Unfortunately, I am having trouble getting "Peakfit" to fit the data in any
meaningful way.

Fitting intensities with the default sigma and gamma seems to work,
although with huge residuals as my peaks are much broader than the defaults.

Fitting position appears to do nothing. If I manually move the position to
the shoulder of the peak, it remains there after the fit.

Fitting Sigma and Gamma manually yield negative values for these
parameters, and I cannot get these to stabilize as positive values. If I
opt instead to fit the instrument parameters UVWXY, these also wind up
vastly incorrect.

I am trying to follow this tutorial:
https://subversion.xray.aps.anl.gov/pyGSAS/Tutorials/FitPeaks/Fit%20Peaks.htm
.

Any help would be appreciated. Thanks and best,

Ari
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