On Sun, 2013-09-01 at 22:28 +0200, James Holton wrote:
> ... but Bragg's genius was in simplifying all this to a little
> rule which tells you how much to turn the crystal to see a given spot.
> We sort of take this for granted now that we have automated
> diffractometers that do all the math
s answer. I had also been wondering about it. To
clearify it for myself, and maybe for a few other bulletin board readers, I
reworked the Bragg formula to:
sin(theta) = n*Lamda / 2*d
which means that if we take n=2, for the same sin(theta) d becomes twice as big
as well, which means that we des
On 22 August 2013 07:54, James Holton wrote:
> Well, yes, but that's something of an anachronism. Technically, a
> "Miller index" of h,k,l can only be a triplet of prime numbers (Miller, W.
> (1839). A treatise on crystallography. For J. & JJ Deighton.). This is
> because Miller was trying to
Dear Pietro,
The n in Bragg's Law is indeed most interesting for teachers and a most
delicate matter for those enquiring about it.
The diffraction grating equation, from which W L Bragg got the idea, a 'cheap
accolade' he said to have it named after him in his Scientific American
article, has
cp4bb] Dependency of theta on n/d in Bragg's law
Dear Pietro,
Ladd & Palmer book does explain it, just first example that springs to mind.
HTH
D
-Original Message-
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Pietro
Roversi
Sent: 20 August 2013 15:37
To:
Well, yes, but that's something of an anachronism. Technically, a
"Miller index" of h,k,l can only be a triplet of prime numbers (Miller,
W. (1839). A treatise on crystallography. For J. & JJ Deighton.). This
is because Miller was trying to explain crystal facets, and facets don't
have "har
Dear Pietro,
Ladd & Palmer book does explain it, just first example that springs to mind.
HTH
D
-Original Message-
From: CCP4 bulletin board [mailto:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Pietro
Roversi
Sent: 20 August 2013 15:37
To: ccp4bb
Subject: [ccp4bb] Dependency of theta on n/d in
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Dear Pietro,
You may take a textbook into account which deals with Laue
diffraction. If you search for the keyword "Laue" and the author
"Helliwell" at the IUCR journals, you will get a large number of hits,
indicating that this is by no means a 'triv
