iucr

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principles
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quantum crystallography
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crystallography in art and cultural heritage
crystallography of materials
electron crystallography
high pressure
inorganic and mineral structures
international tables
journals
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congress

2020 iucr xxv
2017 iucr xxiv
2014 iucr xxiii
2011 iucr xxii
2008 iucr xxi
2005 iucr xx
2002 iucr xix
1999 iucr xviii
1996 iucr xvii
1993 iucr xvi
1990 iucr xv
1987 iucr xiv
1984 iucr xiii
1981 iucr xii
1978 iucr xi
1975 iucr x
1972 iucr ix
1969 iucr viii
1966 iucr vii
1963 iucr vi
1960 iucr v
1957 iucr iv
1954 iucr iii
1951 iucr ii
1948 iucr i

people

nobel prize

all
agre
anfinsen
barkla
boyer
w.h.bragg
w.l.bragg
brockhouse
de broglie
charpak
crick
curl
davisson
debye
deisenhofer
geim
de gennes
hauptman
hodgkin
huber
karle
karplus
kendrew
klug
kobilka
kornberg
kroto
laue
lefkowitz
levitt
lipscomb
mackinnon
michel
novoselov
pauling
perutz
ramakrishnan
roentgen
shechtman
shull
skou
smalley
steitz
sumner
thomson
walker
warshel
watson
wilkins
yonath

resources

commissions

aperiodic crystals
biological macromolecules
quantum crystallography
crystal growth and characterization of materials
crystallographic computing
crystallographic nomenclature
crystallographic teaching
crystallography in art and cultural heritage
crystallography of materials
electron crystallography
high pressure
inorganic and mineral structures
international tables
journals
magnetic structures
mathematical and theoretical crystallography
neutron scattering
NMR crystallography
powder diffraction
small-angle scattering
structural chemistry
synchrotron radiation
xafs

outreach

openlabs

calendar
OpenLab Costa Rica
IUCr-IUPAP-ICTP OpenLab Senegal
Bruker OpenLab Cameroon
Rigaku OpenLab Bolivia
Bruker OpenLab Albania
Bruker OpenLab Uruguay 2
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grenoble-darmstadt
Agilent OpenLab Turkey
Bruker OpenLab Indonesia
Bruker OpenLab Uruguay
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Bruker OpenLab Morocco
Agilent OpenLab Argentina
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- Letter from the President
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- Beevers-Lipson strips
- G. A. Jeffrey - a note
- Peter Goodman (1928-1999)

Today, when Fourier transforms on several thousand data items for large, three dimensional unit cells at a resolution of about 0.3 Å require less time than it takes to gulp down a cup of coffee, it is difficult to imagine the size of the task confronting early crystallographers, where this operation was almost unthinkable. After all, even a two dimensional summation of: S {A cos 2p (hx+ky) + B sin 2p (hx+ky)} for 500 data items into 2000 points requires 106 summations, let alone any work required to calculate the trigonometric functions! The boxes of strips themselves have virtually disappeared although they were once almost universal in the crystallographic community. A handsome box still survives in the Clarendon Lab at Oxford U. The great contribution of Beevers and Lipson in 1936 was twofold: to simplify the calculations greatly by factorizing the trigonometric expressions to reduce the two dimensional calculations to many fewer one dimensional ones, and to provide a convenient technique for carrying out the summations - the strips themselves.

Some people used mechanical calculators for the sums, but most found it far quicker and more accurate to use mental arithmetic, a skill more widely found then than now.

Bob GouldFrom the BCA Newsletter, Dec. 1998

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