[RMCProfile-users] Instrumental resolution with different datasets

stefano checchia stefano.checchia at gmx.com
Tue Mar 22 18:52:05 GMT 2016

Good evening,

I've got a few questions concerning the way RMCprofile handles 
instrumental resolution.
Premise: I'm currently trying to understand why both the D(r) and F(Q) 
functions calculated in my RMC runs, apparently, don't match very well 
the decay of the experimental D(r) and F(Q). As a result, unwanted 
disorder might be introduced in the model, just like the footnote in 
p.10 of the manual of v.6.5.2 points out. This is best observed in the 
D(r) fit residual at different stages of the calculation, in which the 
RMC D(r) fits more accurately either the low-r range or the high-r range 
depending on the disorder in the model.

Initialising the Bragg refinement of TOF data produces the .instfile 
containing one block of diffractometer constants and profile parameters 
for each of the detector banks. During the RMC run, the Bragg fit of the 
histogram I selected in the get_gsas_braggroutine (say histogram 4 from 
bank 4) will obviously be based on the parameters of bank 4. But since 
I'm not declaring which detector banks were used for getting the total 
scattering data (and the respective fits are not affected by histogram 
choice) does RMC take into account all the detector banks provided in 
the .instfile when fitting to the D(r) and F(Q)?

If so, is this behavior enabled by the RESOLUTION_CONVOLUTIONflag? Is it 
ignored otherwise?
Can the resolution correction described in the /MCGRtof/ paper be 
applied as suggested in the manual?

Should I include in the .instfile the detector banks that were ignored 
for the sake of practicality during the Rietveld refinement?

Is the F(Q) endpoint the part of the input defining the Qmax for PDF 

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.rmcprofile.org/pipermail/rmcprofile-users/attachments/20160322/086c2083/attachment.html>

More information about the rmcprofile-users mailing list