Also do you mean error (as in correct value) or calculated statistical uncertainty?
Saul On Wed, Jul 27, 2016 at 9:22 AM, "Łukasz Kruszewski" <lkruszew...@twarda.pan.pl> wrote: > Dera friends, > > I'm doing Rietveld refinements in TOPAS; I get rather good fit of the > reflections, rather good wt.%, but I've observed large errors for the > CrySize (Lorentzian) values for some introduced Structures. I've tried to > change it by refining CrySize (Gaussian), but it only changed in few > particular cases. I'm rather sure that the intrumental parameters > (geometry of the diffractometer was analyzed with the use of LaB6, Si, and > other standards) and corrections (sample displ. etc.) are OK and I suppose > these factors shouldn't influence (?) the CrySize values. I always > constrain the minimum (20 starting value) and maximum (10000 nm) value for > CrySize; I usually refine strain, but I've noticed that it doesn't > influence the results (at least the wt.% calculated). Rwp, goodness of fit > and Durbin-Watson statistics R values are OK; also, the calculated > background line is "flat", i.e., there is no mistaking of the background > with reflections; the shapes of the reflections in the calculated > diffractograms seem to be OK, too. I was thus wondering if these high > errors coming from the CrySize are that important for the refinement? > > Best regards, > > > -- > Łukasz Kruszewski, Ph.D., adjunct > Polish Academy of Sciences > Institute of Geological Sciences > Twarda 51/55 str. > 00-818 Warsaw > Poland > > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> > Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text > The Rietveld_L list archive is on > http://www.mail-archive.com/rietveld_l@ill.fr/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > >
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Please do NOT attach files to the whole list <alan.he...@neutronoptics.com> Send commands to <lists...@ill.fr> eg: HELP as the subject with no body text The Rietveld_L list archive is on http://www.mail-archive.com/rietveld_l@ill.fr/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
