Re: GSAS ESD/STD conversion

[Brian H. Toby]

I am trying to convert a GSAS ESD file to a GSAS STD file There is a problem here that cannot be solved by any conversion program. One typically uses the GSAS ESD format for data that are scaled in some fashion, so that estimated errors (s.u.'s) on the intensity values are not the square roots of the intensity values. Stripping out the s.u.'s means that your statistical uncertainties (& chi**2) are now potentially meaningless and that some parts of your pattern could be over/under-weighted with respect to other parts.  I think that CMPR can plot the ratio of sqrt(I)/sigma (which should be 1 for all points, if you have intensities  as counts). Doing that will give you an idea of what the optimum multiplication factor would be and how bad the idea of dropping s.u.'s will be for your data (how the scaling deviations from a constant) -- if you are going to ignore my cautions. BTW, I would be surprised if FullProf does not have a way to input intensities with uncertainties rather than assuming intensities are counts. Brian ********************************************************************  Brian H. Toby, Ph.D.                            office: 630-252-5488 Materials Characterization Group Leader, Advanced Photon Source 9700 S. Cass Ave, Bldg. 433/D003             work cell: 630-327-8426      Argonne National Laboratory         secretary (Kristy): 630-252-5453 Argonne, IL 60439-4856         e-mail: brian dot toby at anl dot gov  ********************************************************************