Hi Dave,
The circles are quite prominent in the "inner circle (lune)" that you
highlight but not in the next one. The full image is too small to see
details but I don't see any clear circular halos for any of the other
lunes. If you start with the lune going through the origin and number it
zero, then the one with the halos is lune 7. Any chance that there is a
pseudo translation with a periodicity of ~1/7th of the reciprocal vector
perpendicular to the planes that form the lunes.
The pseudo-2D lattice with the halos suggest
hexagonal/trigonal/rhombohedral lattice and the halo radius is half the
reciprocal unit cell length. Maybe you have some weird stacked
rhombohedral packing where two or more rhombohedral cells intercalate so
that there are pure rhombohedral unit cell axes that apply to all atoms
and some pseudo translations that related an atom in one rhombohedral
lattice to one in another stacked lattice. Don't know if that makes sense.
It would be interesting to see some images before and after this one.
Are the halos circles in reciprocal space or spheres that just look like
circles on the oscillation image because the intersection of a sphere
with the Ewald sphere looks like a circle.
On images where the 6th, 5th etc lune forms a 2D lattice do you see the
halo's or is it only on the 7th.
As John said you may well have a collectors item but it would sure be
nice to know what caused this even if structure determination is not in
the cards.
Bart
On 10-10-29 10:08 AM, David Goldstone wrote:
Dear All,
Does anyone have any insight into what the circles around the spots
might be?
cheers
Dave
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Bart Hazes (Associate Professor)
Dept. of Medical Microbiology& Immunology
University of Alberta
1-15 Medical Sciences Building
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Canada, T6G 2H7
phone: 1-780-492-0042
fax: 1-780-492-7521
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