Re: Monte Carlo, Genetic Algorithms (...) for Powder Structure

Jens Wenzel Andreasen ( (no email) )
Wed, 28 Jan 1998 23:22:20 GMT+1

Please, don't take this off-line. It is extremely interesting to
follow.
-Jens

> Well, looks like they're lining up!! You've got a discussion going,
> Lachlan!
>
> So here's some more fat in the fire! Major figures though Alan, Armel
> and Bob are, I suspect their comments stems from a lack of personal
> experience in the use of the correlated integrated intensity method
> of refinement. We experimentalists who use the technique find that it
> works very well indeed - our latest structure solution success from
> the ESRF shows the two methods - Rietveld and correlated integrated
> intensity methods producing the same results.
>
>
> Alan,
> True to your request, Alan, I will lead you through it step by step
> off-line - it's not statistics but simply matrix algebra and we
> experimentalists who are doing structure solution find that the two
> techniques work very well in practice. And by the way, as a happy
> coincidence, the combined use of Pawley and Rietveld methods gives
> the sort of esds increases that Dave Cox majors on and we all know
> about.
>
> Armel,
> Your problem about equipartioning applies to the data not to the
> model. Again, I'll go through that off-line with you if you want.
>
> Bob,
> Again, I'll go into the details off-line as I guess that they are
> beyond the interests of most of the mailing list. Suffice to say
> that, in practice, the two methods give the same results.
>
> Now I wonder which of you is going to get our J. Appl. Cryst. to
> review!!!
>
> Bill
>
>
Jens Wenzel Andreasen "If only those geologists would let me
Dept. of Mineralogy alone, I could do very well, but those
Institute of Geology dreadful hammers! I hear the clink of
University of Copenhagen them at the end of every cadece of the
Phone: +45 33 25 20 60 Bible verses." - John Ruskin, 1851