Brian Toby a écrit :
If the numbers are real values then they are not counts. They may be counts per second or something else. One needs to have uncertainty estimates for these intensities before one can do a meaningful Rietveld refinement (with any code). Following the above procedure, by multiplying them by an arbitrary constant and then inputting them to GSAS as if they were counts will cause GSAS to compute the uncertainties as the square-root of the intensities, something that is quite unlikely to be true. This will cause the refinement to be weighted improperly and the "r-factors" to be wrong.
Hi
That's right. However, one can get something like 'real counts' if we measure several times and "merge" the data. Of course in this case you have the esd's and one should use it ! In Powder the "real" counts are converted to the nearest integer for the conversion to GSAS and other programs.
Regards
PS As for the attachement to the list, for this particular case it was important to have the whole file to spot the problem. I often get info for bugs in Powder4 and while I am sure there are plenty of them -at least a pair- most of the reported problems are actually data files with problems. So guys, look at the data files first (with PFE or Notepad) then try to convert them.
