Re: Distribution of cell edge lengths

Brett Hunter ( bah@ansto.gov.au )
Tue, 25 Nov 1997 09:04:42 +1100

HI Helge,
I am not sure this will help, but the simplest approach is to go
through the following arguments:

If you have a lattice spread equal to delta p (where p is one of the
lattice constants)
then the spread in theta will be via bragg's law:

delta theta
-------------- = C tan(theta)
delta p

(C is a constant that can be worked out for particular cases)

this means FWHM = sqrt[ (Uo + 2C delta p)tan2(theta) + ...]

I am sure there are more elegant ways of doing this as well.
(See Elcombe and Howard in Materials Science Forum Vol 27/28 (1988) p71-76
for more details)

Ciao
Brett

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