On Tue, 25 May 1999, Alan Hewat, ILL Grenoble wrote:
> >>I guess the degradation which is found would come from parameters which
> >>are determined by both datasets and come out with different values in each
> >>separate refinement.
>
> If they come out differently it is because they are differently biased by
> different systematic errors in the data not described by the model.
I was thinking of C-H (D) bondlengths from x-ray and neutron data. Don't
they come out differently if you use spherical form factors for the x-ray
data? I guess a neutron expert might look on this as an systematic error
in the x-ray model :) Maybe not if one looks on the x-ray refinement as
fitting of the electron density function, rather than the nuclear
positions. For bonding studies it is the differences which are of
interest!
Jon Wright.
PS: Any offers other than GSAS and multipattern fullprof for actually
doing these fits?
