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Re: [sdpd] how to purchase a high resolution diffractometer
In general, if I had to carry out indexing work from a *single* set
of powder diffraction data, I would prefer it to be collected in
transmission geometry (because of fewer systematic errors) under
conditions giving maximum resolution (and hence reduced intensity, at
least in the case of a lab instrument), and slowly (to recover some
of that lost intensity).
On the other hand, the new specimen-displacement correction
facilities within Crysfire 2000 for reflection datasets are
intended to go some way to restoring the balance between transmission
and reflection geometries, both for self-calibration and for
dataset correction generally.
Finally, where feasible I like to compare and combine the results
from *several* datasets collected under *different* conditions of
geometry, preferred orientation, etc., so as to capture as much
information as possible about the sample before investing in indexing
computations, especially in important and difficult cases.
Robin Shirley
School of Human Sciences
University of Surrey
----------------------------------------------------------
To: sdpd...@egroups.com
From: "L. Cranswick" <L.M.D.Cranswick...@dl.ac.uk>
Date: Sun, 8 Oct 2000 17:02:28 +0100 (BST)
Reply-to: sdpd...@egroups.com
Subject: Re: [sdpd] how to purchase a high resolution diffractometer
For indexing purposes - how would the "transmission" mode system compare
to a Bragg-Brentano reflection system?
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
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