Hi Tammy,
There is a brief mention of simultaneous X-ray neutron refinements in Young's
Book "The Rietveld Method". GSAS and a few other packages can do this (can
FullProf?). There are 2 main problems on a simplistic level. Firstly, X-rays
see the electron density and neutrons the nucleus. This means that the atom
positions are not necessarily the same. Secondly, the applicability of
orientation, absorption, etc corrections are different in the two cases and as
the codes that exist (please correct me if anyone knows better) assume equal
weighting for both data sets this can lead to a mess, if for instance
preferrered orientation parameters are well described with neutrons but not
with X-rays.
I think that simultaneous refinement (X-ray and neutron, or using different
wavelengths so that the refinement has high angle peaks and higher 'effective'
resolution data) is a nice topic for discussion and would be interested in the
views of others...
-Andrew
---------------
Andrew S. Wills (Dr)
Centre D'Études Nucléaires de Grenoble, France
>On a somewhat unrelated note, can someone recommend any references which
>describe simultaneous structure determination by x-ray and neutron
>diffraction? I have read only vague descriptions of this method, but no
>actual strategies have been revealed.
>Thank you in advance for any assistance that you may be able to provide.
>Best regards,
>Tammy
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