I'm not familiar with Jade, and from your description I may only speculate that such difference in calculated RIRs for the same structure may be caused by erroneous interpretation of the structure input files by the program (space group, site occupancies, etc.) or typos in the input.
******************************************************* Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660036, Akademgorodok 50/24, Krasnoyarsk, Russia http://sites.google.com/site/solovyovleonid ******************************************************* ----- Original Message ----- From: "Chrysochoou, Maria" <mchry...@engr.uconn.edu> To: Leonid Solovyov <l_solov...@yahoo.com> Cc: Sent: Wednesday, April 2, 2014 5:07 PM Subject: RE: Reference Intensity Ratio of clay minerals I am using Jade to do Whole PAttern Fitting, which utilizes structural models like you said. Even though you cannot change the RIR because it is calculated from the structure, you can see it, and my understanding is that it is related (directly or indirectly) to the estimation of the quantities of each mineral. I have two different structures for vermiculite, one of which results in 1.6% VM (and the calculated RIR is 22) and another one which results in 6% VM (and the calculated RIR is 8). The fit is similar in both cases. Does this make sense? ________________________________________ From: rietveld_l-requ...@ill.fr [rietveld_l-requ...@ill.fr] on behalf of Leonid Solovyov [l_solov...@yahoo.com] Sent: Wednesday, April 02, 2014 5:47 AM To: rietveld_l@ill.fr Subject: Re: Reference Intensity Ratio of clay minerals The Rietveld-QPA doesn’t require RIR, as the peak intensities of phases are calculated from the structure models. What do you mean under “doing Rietveld” and ”structural files” in your case? ******************************************************* Leonid A. Solovyov Institute of Chemistry and Chemical Technology 660036, Akademgorodok 50/24, Krasnoyarsk, Russia http://sites.google.com/site/solovyovleonid ******************************************************* ----- Original Message ----- From: "Chrysochoou, Maria" <mchry...@engr.uconn.edu> To: "rietveld_l@ill.fr" <rietveld_l@ill.fr> Cc: Sent: Wednesday, April 2, 2014 4:21 PM Subject: Reference Intensity Ratio of clay minerals Hello, I am wondering why the RIR of clay minerals such as vermiculite and montmorillonite is so high in the structural files (e.g. around 22-28). I am not a crystallographer, but I have noticed that high RIRs are usually associated with dense structures and heavy elements and neither is the case with clays. And for example, kaolinite and illite have much lower RIRs, 1 and 0.5, even though the structures are not that much different. This results in very very low concentrations when doing Rietveld, even though there is substantial intensity associated with vermiculite and it does not make intuitive sense to me. I would appreciate any insight into this question. Thank you, Maria Chrysochoou Associate Professor Department of Civil and Environmental Engineering University of Connecticut ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 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/ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
