Hi Regarding " Issues with sequential refinement (Nick Weadock)", I also had similar problem. In May 15 2017 I wrote to gsas ii digest:
========= Dear everyone I try to do sequential refinement for Sc-doped TiO2 while in-situ heated at 25-1200C temperature range, total of 33 histograms. As a function of temperature I have different lattice parameters, ratio of anatase / rutile and crystallite size/microstrains. I tried to refine them at that sequence usin GSAS-II. After working on lattice parameters (DXX, hydrostatic/elastic strain terms) I tried to refine the ratio of anatase / rutile and/or crystallite size/microstrains and got a "Sequential refinement error" message: Invalid metric tensor Cell/Dij refinement not advised Sometimes I can't get the Sequential results, although I "see" that the DXX have different values. Even if I manage to get the results on table, I can't get them in graph as lattice parameters (instead I get DXX) Best regards, Victor ========= Eventually I had to restart the calculations in order to make them work properly, not sure what went wrong. In fact some of these 'sequential refinement ' worked fine, some wasn't good. The problem was that I always use the former values of the refinement to the next pattern's refinement. I had 33 diffractions patterns from RT to 1200C. I divided them into 2 separate 'sequential refinement ', but eventually I repeated all of them manually. I have to mention that I did these 'sequential refinements' 3-4 months ago, using older versions of GSAS-II. Maybe it got better. Also I was less experienced with GSAS-II :) Hope it will help Victor 2017-11-15 20:00 GMT+02:00 <gsas-ii-requ...@aps.anl.gov>: > Send GSAS-II mailing list submissions to > gsas-ii@mailman.aps.anl.gov > > To subscribe or unsubscribe via the World Wide Web, visit > https://mailman.aps.anl.gov/mailman/listinfo/gsas-ii > or, via email, send a message with subject or body 'help' to > gsas-ii-requ...@mailman.aps.anl.gov > > You can reach the person managing the list at > gsas-ii-ow...@mailman.aps.anl.gov > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of GSAS-II digest..." > > > Today's Topics: > > 1. Issues with sequential refinement (Nick Weadock) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Tue, 14 Nov 2017 15:25:43 -0800 > From: Nick Weadock <nwead...@caltech.edu> > To: gsas-ii@mailman.aps.anl.gov > Subject: [GSAS-II] Issues with sequential refinement > Message-ID: > <CAO0QVOqyfUmnPMTwp18VmbEaskxV-gssaC-hO_EAQzaybt77Jw@mail. > gmail.com> > Content-Type: text/plain; charset="utf-8" > > Hi, > > I am having some issues with a sequential refinement in GSAS. I have been > following along with the tutorial here: > https://subversion.xray.aps.anl.gov/pyGSAS/Tutorials/ > SeqRefine/SequentialTutorial.htm > to limited success. > > Previously, I had trouble getting the phase fractions to sum to 1. I would > put the "wildcard" constraint in as stated in the tutorial, but the phase > fractions still would not sum to 1 after the refinement. I re-did the > tutorial and got it to work, however. > > I am trying the tutorial again, but have been running into the following > exception: 'invalid metric tensor \n cell/Dij refinement not advised' I did > not run into this problem previously. > > Has anyone had experience with similar issues in sequential refinement? I > am trying to perform sequential refinement of my own data, but had the same > issues with the phase fractions. A colleague performed a sequential > refinement on the same data but the phase fractions worked out fine for > them. > > I am using the most up to date version of GSAS-II. Any help would be > greatly appreciated, > -- > Nick Weadock > PhD Candidate, Materials Science > California Institute of Technology > 1200 E California Blvd, Pasadena, CA 91125 > MC 138-78 > x2520 > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: <http://mailman.aps.anl.gov/pipermail/gsas-ii/attachments/ > 20171114/bce4dd31/attachment-0001.html> > > ------------------------------ > > _______________________________________________ > GSAS-II mailing list > GSAS-II@mailman.aps.anl.gov > https://mailman.aps.anl.gov/mailman/listinfo/gsas-ii > > End of GSAS-II Digest, Vol 143, Issue 1 > *************************************** >
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