[ccp4bb]: error propagation on anisotropic thermal parameters

["Ulrich K. Genick" <genick@brandeis.edu>]

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Has somebody in the past worked out
how to propperly propagate errors when
extracting the eigenvectors and eigenvalues
from the 6 U parameters output by SHELX.

In other words, I know the esds for the
U parameters and want to calculate the
esds for the components of the 3
Eigenvectors and the 3 Eigenvalues.

I assume this has been worked out
by somebody in the past and is probably
published in a small molecule paper
somewhere.

If anybody know a reference or even
better has code, I can
save myself and my rusty math skills
the trouble of forming
the derivatives of all the
transformation equations
or do monte carlo style stuff.


I want to code this into a program, so
"run-it-through-program-a-b-and-c-and-then-
eyeball-it-in-O" type answers will not do
me much good.


Ulrich


-- 
Ulrich K. Genick
Assistant Professor
Department of Biochemistry
Brandeis University, MS009
Waltham, MA, 02454

Room   Kosow 108
Phone  781-736 2304
Fax    781-736 2349
Email  genick@brandeis.edu