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> Heisenberg was probably here!
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> *From:* CCP4 bulletin board *On Behalf Of *James
> Holton
> *Sent:* Thursday, May 28, 2020 11:34 AM
> *To:* CCP4BB@JISCMAIL.AC.UK
> *Subject:* Re: [ccp4bb] Strange Pseudosymmetry Effects
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Hi Tim
You could send out an SOS to some of the other authors in the same issue, who
might have kept a copy - several are “regular" posters on this forum, e.g.
Sacha Urzhumtsev
Gerard Kleywegt
Eleanor Dodson
There’s a good chance they’ll be stuck at home at the moment
tin board On Behalf Of James
> Holton Sent: Thursday, May 28, 2020 11:34 AM
> To: CCP4BB@JISCMAIL.AC.UK
> Subject: Re: [ccp4bb] Strange Pseudosymmetry Effects
>
> Be careful with electron diffraction and apparent absence violations.
> It is possible these weak spots are simply due t
lo.edu<mailto:esn...@hwi.buffalo.edu>
Webpage: https://hwi.buffalo.edu/scientist-directory/snell/
[hwilogo]
Heisenberg was probably here!
From: CCP4 bulletin board On Behalf Of James Holton
Sent: Thursday, May 28, 2020 11:34 AM
To: CCP4BB@JISCMAIL.AC.UK
Subject: Re: [ccp4bb] Strange Pseudosymm
Be careful with electron diffraction and apparent absence violations. It
is possible these weak spots are simply due to multiple scattering. If
so, you would see them relatively stronger with larger crystals,but much
weaker relative to the strong reflections when the crystal is smaller.
Do
Yes - in P1 if you have two molecules approximately related by
X y z. And x+ 1/2 y z say then the spots along the axis a* will have h=2n
weak. And the sections with h even will have very weak spots. If you
calculate a Patterson for the data there will be a strong peak st 1/2, 0,0.
But you say
On Wednesday, 27 May 2020 18:49:23 PDT Jessica Bruhn wrote:
> Hello,
>
> I am wondering if pseudosymmetry can cause weak reflections that mimic the
> doubling of one unit cell axis' length. Has anyone seen something like this
> before?
Yes.
> I am processing data from a small molecule sample
Hi Jessica,
If you see spots and they fit a lattice, you should use them. Use the b=10
solution in P1 that you have with 3 models (or two if one is iffy) and use
that as a start model for MR in b=20 and start searching for the rest.
Alternatively, use the b=10 model with stuff that looks decent
Hello,
I am wondering if pseudosymmetry can cause weak reflections that mimic the
doubling of one unit cell axis' length. Has anyone seen something like this
before?
I am processing data from a small molecule sample collected with electron
diffraction from multiple crystals. For the b axis, it
