There are two possible interpretations of this 1. That I am trying to get
people to read or perhaps reference some of my papers or 2. that I am
trying to sell code.
1. My papers, along with most others, contribute to a matrix of
understanding of problems, materials or analysis procedures. They along
with the sometimes associated programs are simply mile markers along the
learning curve and I don't give a tinkers-damn if anyone references them.
In fact it is this matrix that the more experienced people are making
available to younger researchers on the Rietveld mailing list (and
apparently for which they are going to take some flames from the dimmer
participants).
2. Codes developed in my lab are associated with graduate thesis research and
are always in the public domain. Some students have gone on to develop PC
versions of some of these programs for sale but I would have thought that
reference to an anonymous FTP address would have clearly indicated the code
was free, including source and manuals.
Now that I hope it is clear that I am giving codes away to anyone who may
wish to use them, let me go on to address the confused understanding
that Mr. LeBail has about SHADOW.
No matter how much effort I put into writing manuals (or papers, in vain
hopes they will be referenced!) it seems there are always those like Mr. Le
Bail who hopelessly miss the most fundamental points. SHADOW implements
what I call a Parrish style deconvolution. That is to say the instrument
profile (with all of its asymmetry) is carefully modeled with split
Pearson functions. A specimen broadening function (which may also be
modeled with an asymmetric split Pearson) - is convoluted with the
instrument profile to establish the shape of S. In the simplest mode the
theta dependence of the FWHM of S is modeled with simple isotropic size
and strain formulae. However, as I pointed out in my original note,
stacking fault asymmetries would be easy to incorporate. We have since
had two other messages which indicate that there are codes which apparently
have already incorporated this model and are therefore obviously preferable
for this problem. The Rietveld type asymmetry factor was also put into the
SHADOW program apparently just to confuse people like Mr. Le Bail.
Any further flames from Mr. Le Bail will be responded to directly to his
address. I will not further contaminate all of your mailboxes with such
nonsense. I hope Mr. Le Bail's thoughtless comments do not discourage use
of this mailbox by those in fear of such flames.
Bob Snyder