I fully agree with you that sample height is the one parameter to refine
and that and that this parameter has a rather different angular
dependence. However, in agreement with Rory experience we are never able
to refine sample height in Bragg-Brentano geometry on the Siemens D5000
with alpha1. We found that the correlation between those parameters was
always close to 100%. And yes this is with data collected up to 120 deg 2
theta. By the way how do you model your asymmetric peak shapes? I allways
find that this parameter in the peak profile correlates highly with all
the parameters mentioned earlier, including the lattice parameters.
Jaap Vente
Inorganic Chemistry Laboratory
Department of Chemistry
University of Oxford
South Parks Road
Oxford, OX1 3QR
United Kingdom
E-mail: jaap.vente@chem.ox.ac.uk
tel: (..44)(0)1865-272602
Fax: (..44)(0)1865-272690