Hello Peter. Thank you very much. I will do so and check it. I find this mailing list very useful - a lot of useful informations from kind people that like to share - thank you!
Best regards, Łukasz Kruszewski > If you switch from GUI mode to launch mode and perform refinement, you > will > see correlation matrix at the end of .inp file and can tell which > parameters correlate a lot and figure out what's causing such large error. > I also think that this error is not strange for such large cryst.size as > it > is basically beyond the limt of the methods. > Peter > > .................................................................... > Dr. Peter Y. Zavalij > Director - X-ray Crystallographic Center > University of Maryland, College Park, MD 20832 > > On Wed, Jul 27, 2016 at 1:07 PM, "Łukasz Kruszewski" < > lkruszew...@twarda.pan.pl> wrote: > >> Hello James. I just read the error that is reported for each refined >> parameter in TOPAS. I obtain value like, e.g., 9000 nm, and the error >> is, >> e.g., 205006. >> >> Best regards, >> >> Łukasz Kruszewski >> >> >> > By what metric are you determining that the CrySize value is in error? >> > >> > >> > James P. Cline >> > Materials Measurement Science Division >> > National Institute of Standards and Technology >> > 100 Bureau Dr. stop 8520 [ B113 / Bldg 217 ] >> > Gaithersburg, MD 20899-8523 USA >> > jcl...@nist.gov >> > (301) 975 5793 >> > FAX (301) 975 5334 >> > >> > -----Original Message----- >> > From: rietveld_l-requ...@ill.fr [mailto:rietveld_l-requ...@ill.fr] On >> > Behalf Of "Lukasz Kruszewski" >> > Sent: Wednesday, July 27, 2016 10:22 AM >> > To: rietveld_l@ill.fr >> > Subject: CrySize error in TOPAS >> > >> > 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 >> > >> >> >> -- >> 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/ > ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ > > -- 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/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
