An interesting discussion of the development of the Debye-Waller
correction can be found in the IUCr publication, "Fifty Years of X-
Ray Diffraction," edited by P.P. Ewald (unfortunately, it's no longer
in print). It seems that Debye was the first scientist to tackle "a
problem which appeared to others hopelessly complicated at the time:
the influence of the temperature motion of the atoms on the
diffraction of X-rays (p. 79 of aforementioned publication)."
Interestingly, his original formulation of the correction included
the constant M, "which can be expressed by means of the elastic
properties of the crystal or their combination, the 'Debye
Temperature', which occurs in the theory of the specific heat (same
reference)." The text goes on to mention that Ivar Waller
demonstrated in 1923 that Debye's expression for M was wrong by a
factor of two. No mention is given in "Fifty Years" of a "B factor"
but it sounds as though Waller decided to use a different
nomenclature in his paper from 1927 to avoid confusion.
Too bad that "Fifty Years" is no longer in print, though used copies
can be purchased from various on-line booksellers. It provides a very
enlightening and easily readable history of the early days in the
field, and the interchange of scientists and ideas across the
Atlantic Ocean.
Diana
On Jan 24, 2007, at 11:14 AM, Santarsiero, Bernard D. wrote:
It looks like the earliest reference to the Debye-Waller factor is
from
Debye's paper:
Uber den Einfluss der Warmebewegung uf die Interferenzerscheinungen
beiu
Rontgenstrahlen, Verhandl. deut. phyik. Ges., 15, 678-689 (1913),
and the succeeding paper Verhandl. deut. phyik, Ges., 15, 738-752
(1913),
and Waller:
Die Einwirkung der Warmbewegung der Kristllatome auf Intersitat,
Lage, and
Scharfe der Rontgenspektrallinein, Ann. Physik, 83, 153-183 (1927).
Interestingly, beta was used for the anisotropic Gaussian form of the
isotropic Gaussian B-factor.
Bernie
On Wed, January 24, 2007 9:05 am, Roberto Steiner wrote:
Hi Rajesh,
I also wondered about that.
Not having been able to find a good explanation in the literature
I thought of it as reducing factor of the *B*ragg peaks. Mhhhh???
Then I stopped thinking about it (I now try to call them ADPs)
Roberto
On 24 Jan 2007, at 12:42, Rajesh Kumar Singh wrote:
May be too trivial, I was just wondering
what "B" stands for in the term "B-factor".
Thanks
Rajesh
--
Rajesh Kumar Singh
Institut fur Biochemie
Universitat Greifswald
Felix-Hausdorff-Str. 4
D-17489 Greifswald
Germany
E.Mail: [EMAIL PROTECTED]
Phone: +49-3834- 86 4392
---
Dr. Roberto Steiner
Randall Division of Cell and Molecular Biophysics
New Hunt's House
King's College London
Guy's Campus
London, SE1 1UL
Phone +44 (0)20-7848-8216
Fax +44 (0)20-7848-6435
e-mail [EMAIL PROTECTED]
* * * * * * * * * * * * * * * * * * * * * * * * * * * *
Diana R. Tomchick
Associate Professor
University of Texas Southwestern Medical Center
Department of Biochemistry
5323 Harry Hines Blvd.
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Dallas, TX 75390-8816, U.S.A.
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