I did high pressure diamond anvil experiments without a hydrostatic medium. I used GSAS-2 to analyze the data. Instrument parameters were determined according to the LaB6 calibrant scan.

When I imported the data, the peaks are broad. I refine the background, unit cell, and phase fraction.

When I refine the microstrain to improve the fit, it jumps from 1000 to around 40000. Is this a realistic value? Even if I change the type to generalized, the tensor values are really high so the average mustrain is high.

I do not refine the particle size. Not sure if I should. Nor do I refine the instrument parameters after they are determined using the calibrant (as featured in the GSAS-2 tutorials).

I would love some help regarding using rietveld refinment with these high pressure experiments and whether my values are reasonable.