Woops!, yes Randy, I should have written B = 8*pi^2*^2, not
8*pi*^2 in my original response.
Incidentally, the "A factor" of a Lorentzian-distributed atom is 2*pi*w
where "w" is the full-width at half-maximum (FWHM) of the histogram of
displacements.
It is important to remember also that th
Just to clarify what Eleanor is saying:
It was pointed out earlier (by James Holton, if I remember correctly?)
that only the vibration in the direction parallel to the diffraction
vector matters. If the mean-squared vibration in that direction is
1A^2, then the B-factor will be about 80A^2
A small molecule crystallography text would give you the formulation
for an ideal case.
A rough guide is that a B factor of 80 is equivalent to a mean vibration
about the coordinate of 1A
But for proteins the B factor becomes the collection bin for all sorts
of other errors - unrecognised mul
The original reference is Debye, P. (1914) Ann. d. Physik 43, 49, which
is in German. Waller's paper came later and the forgotten paper wich did
the math rigorously was Ott, H. (1935) Ann. d. Physik 23, 169. The best
description I have seen in English was in chapter 1 section 3 of:
James R. W. (
Hello Crystallographers,
does anybody have a good reference dealing with interpretations of what
B-factors (anisotropic or otherwise) really signify? In other words, a
systematic addressing of all of the possible underlying
molecular/crystal/data-collection phenomena which the B-factor mathemat
