On Fri, 7 Jan 2000, Armel Le Bail wrote:
> 15mn for checking a crystallography set is about my
> performance too.
Just out of interest, how long does it take people to pick up the
error in entry number 17280, attached below. It's just a cell
transformation from the cubic spinel [a->(a+b)/2, b->(a-b)/2), c->2c]
> I need more if there is really an error in the original.
Well.... the error is in the original publication as well, but I don't
think this counts. It is just a transformation from the Fd3m setting, so
you could take a=b, beta=90 and have the cubic structure.
Perhaps I am just a bit slow, but I think it would take more than 15
minutes to check this, unless you have access to specialised software?
Happy new year all,
Jon
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COL ICSD Collection Code 35002 (DATE=R821231/U 0 REL= 17280/ 1)
NAME Iron diiron(III) oxide MINR Magnetite low Spinel group
FORM Fe3 O4 = FE3 O4
TITL Structure of magnetite Fe3 O4 below the Verwey transition
temperature
AUT Iizumi M, Koetzle T F, Shirane G, Chikazumi S, Matsui M, Todo S
REF ACBCA 38 (1982) P. 2121-2133
JRNL Acta Crystallographica B (24,1968-38,1982)
CELL A=5.934(1) B=5.925(1) C=16.752(4) �=90.0 �=90.0 �=90.0 V=589.0
Z=8
SGR P m c 21 ( 26)
PARM Atom Nr Ox Wy ---- x ---- ---- y ---- ---- z ---- SOF
Fe 1 +2. 2a 0.0 0.0 0.3125
Fe 2 +2. 2b 0.5 0.0 0.0625
Fe 3 +2. 2b 0.5 0.5 0.1875
Fe 4 +2. 2a 0.0 0.5 0.3125
Fe 5 +3. 4c 0.25 0.5 0.0
Fe 6 +3. 2a 0.0 0.25 0.125
Fe 7 +3. 2a 0.0 0.75 0.125
Fe 8 +3. 4c 0.25 0.0 0.25
Fe 9 +3. 2b 0.5 0.25 0.375
Fe 10 +3. 2b 0.5 0.75 0.375
O 1 -2. 2a 0.0 0.2596 0.0024
O 2 -2. 2b 0.5 0.2596 -0.0024
O 3 -2. 2a 0.0 0.7404 0.0024
O 4 -2. 2b 0.5 0.7404 -0.0024
O 5 -2. 4c 0.2404 0.0 0.1274
O 6 -2. 4c 0.2404 0.5 0.1226
O 7 -2. 2a 0.0 0.2404 0.2476
O 8 -2. 2b 0.5 0.2404 0.2524
O 9 -2. 2a 0.0 0.7596 0.2476
O 10 -2. 2b 0.5 0.7596 0.2524
O 11 -2. 4c 0.2596 0.0 0.3726
O 12 -2. 4c 0.2596 0.5 0.3774
REM M Idealized coordinates derived from structure above 120 K, cp.
35003
V=589.0
M Real cell has a and b doubled, C1c1 with $-beta=90.20(3), Z=32
TEST Calc. density unusual but tolerable
TEST No R value given
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