Re: X-Fit and SPVII, FWHM?

Sue Kesson ( Sue.Kesson@anu.edu.au )
Thu, 17 Sep 1998 09:58:23 +1000

At 02:13 PM 16-09-98 +0200, you wrote:
>Hi all,
>
>when fitting a split PVII to a peak profile,
>one gets the values 2theta, H1 and H2, m1 and m2,
>which are coefficients in the SPVII function. But one
>does not get the FWHM of the peak (especially not
>the FWHM left and right, which one could use for
>describing the asymmetry). Is there a way to
>calculate the FWHM from these coefficients?
>

DBWS can be flagged to give this information in its output file

Which leads me to my own plaintive cry for help. Re: DBWS Split Pearson
function
I've started with the input a successful refinement using the plain-vanilla
Pearson function, and now I want to use the SplitPearson instead. You
wuld think that this would be a simple procedure, beginning by combining
two identical half-profiles etc etc...... Unfortunately, disaster soon
follows.

Has any other fellow sufferer out there got a couple of DBWS input files
that demonstrate successful refinement of the same data using the simple
Pearson function, on the one hand, and Split Pearson on the other? It
would give me some insight into how the parameterisation changes.

ever hopefully yours
Sue

PS Rietveld refinement is one of those few fields of intellectual endeavour
wherein the more one does it, the less one understands.
Dr Sue Kesson

Research School of Earth Sciences
Australian National University
Canberra ACT 0200
Australia

International ph: 61 2 6249 4228
International fax 61 2 6249 5989

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