Dear Mr. Hidetoshi,

When i tried opening the pcr file uploaded by you in Fullprof, i could see the FWHM parameters available for refinement selection.

Possibly there is something wrong with the installation in your computer. I suppose a fresh installation of the latest version should solve the issue.

Attaching the screenshot of the opened pcr file.

I hope it helps.

Dear Mr. Gagan K. Goyal

Thank you for your reply.

I downloaded and installed the latest version of fullplof from the following site, but I still can not input only FWHM parameters.

https://www.ill.eu/sites/fullprof/

There may be a problem on my computer itself, so I try installing Fullprof on another computer.

Sincerely yours,

Hidetoshi Miyazaki

Dear Mr. Gagan K. Goyal

I installed the old version of FullProf Suite and confirmed that I could enter FWHM.

Setup_FullProf_Suite_April2018_64b.exe

It seems that my PC and the latest version were not compatible.

Thank you very much for your help.

Sincerely yours,

Hidetoshi Miyazaki

open the *.pcr file generated by Fullprof with Notepad or another editor (I suggest to use always this choice to manage the *.pcr file; it takes a little time, but when your able with this choice you can view everything at the same time). Then manually change the values of U, V and W; you're using synchrotron radiation, then I suggest to put U=V=0 and start to refine W till convergence; then refine also U and W. I worked a little with your files and you can find the obtained plot in the attachment (Bragg R-factor: 1.50 %; Rf-factor= 1.90 %).

Dear Dr. Alberto Martinelli,

Thank you for your kind advice, very much. As a Fullprof beginner user, advice from a knowledgeable user like you is very helpful.

I performed Rietveld analysis of the standard substance, Ceo2, using Fullprof. I think that Rwp is a little high, but I think that the refinement of the lattice constant has been done without any problems.

However, since the Bragg R-factor is larger than your value, I still need to refine parameters.

I will try various adjustments to make the parameters more precise.

@ Hidetoshi Miyazaki I checked the file.pcr that you attached, but I cannot exactly understand what parameters you are refining, since all are fixed with "0.00000".

In any case don't fix your attention only to the exact values of R_Bragg or R_p; in principle what you obtained is excellent, but when I check you file.pcr there are some incorrect things. for example the "Bov" should be fixed to zero before refining "Biso" (and similarly "Biso" should be fixed to zero befor refining "Bov". Then you refined the preferred orientation with "Pref1" and "Pref2"; you are working with a cubic phase, are you sure that it is oriented? it doesn't seem to me (there's no incresed intensity for selected families of peaks). then, what is the reason why you refined "SySin"? there is evidence in the pattern to do this?

Take care that the goal of Rietveld refinement is to obtained a reliable structural model, not to obtain arbitrary low values of R_parameters. Hence, you must always pay attention to what you are doing, if you select parameters that are physically meaningful.

I don't know how many parameters you refined; I refined only 10 pareameters:

1: scale

2: zero

3: cell parameters

4,5,6: U,V,W

7: Shape1 (using a pseudo-Voigt)

8,9: Biso for Ce and O

10: X

the refinement can be further improved by refining the background (in my case 112 points)

Finally, if you find useful my suggestions, please click on "reccomend", thanks!