Re: [sdpd] Reference materials for calibration and indexing

[L.M.D.Cranswick...@dl.ac.uk]

Can the raw, uncorrected for intensity data for InO3
be put on the site or Emailed to those who are
interested?  (me for starters)  The profiles of the
corrected data would still have to be modelled by
a Variable Slit profile function but not sure what
changing the intensities might be doing - even if only
a minor influence on the Fundamental Parameters fit.

On a slightly related topic.

It would be interesting to test out these new computer
controlled ADS slits vs fixed slits for Rietveld work
given the old mechanical ones used to come in for
criticism as being not as good as fixed slits for providing
reliable intensities (and used to be far more painful
to install and align compared to fixed slits).

Any comments about comparison of modern computer ADS
vs traditional fixed slit systems?  Has the above
been done?

Perhaps the major problem in the past was software not 
completely matched to handling ADS data?  
I remember having an offline (verbal)
discussion around two years ago where it was claimed the 
standard modelling/correction of ADS intensity data using
the 1/(sin theta) correction as being only approximately
correct.  An alternative was proposed based on the 
fundamentals - but unfortuntely cannot remember what that
was.

At the time this probably helped to confirm my prejudice 
for fixed slit data where the physics is known with 
respect to intensities(?)

Lachlan.

-- 
Lachlan M. D. Cranswick

Collaborative Computational Project No 14 (CCP14)
    for Single Crystal and Powder Diffraction
Daresbury Laboratory, Warrington, WA4 4AD U.K
Tel: +44-1925-603703  Fax: +44-1925-603124
E-mail: l.cranswick...@dl.ac.uk  Ext: 3703  Room C14
                           http://www.ccp14.ac.uk