Re: [ccp4bb] tricoordinated ion?

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CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Crystals grown from high ammonium sulphate
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2008-11-04

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Subject: Re: tricoordinated ion?
From: Roger Rowlett rrowlett {- at -} MAIL {- dot -} COLGATE {- dot -} EDU
Date: 2008-11-04

Subject: Re: tricoordinated ion?
From: Klaus Piontek klaus {- dot -} piontek {- at -} OCBC {- dot -} UNI-FREIBURG {- dot -} DE
Date: 2008-11-04

Hi Sebastiano,

I had similar experiences with various crystal structures. After a lot
of modeling (albeit at about 1 A resolution) I came to the conclusion
that these atoms correspond to disordered solvent molecules, e.g. water
and/or Zn. In other words the atoms have occupancies of < 1, but in the
sum it should be 1.

For CO2 or similar molecules the bond length are far too long (C-O is
about 1.4 A or so).

Good luck.

Klaus Piontek

Sebastiano Pasqualato wrote:
> Hi all,
> I wanted to ask you what would you model in the density in which I
> have at the moment modelled 4 water molecules, which are however too
> close to be waters, I guess (see attached image).
> My crystallisation conditions contain NaCl, MgCl2, Peg400, TrisHCl, TCEP,
> glycerol.
> I can't think at a tricoordinated ion like that...
> thanks in advance for the hints,
> ciao
> S
>
>

--
Dr. Klaus Piontek
Albert-Ludwigs-University Freiburg
Institute of Organic Chemistry and Biochemistry, Room 401 H
Albertstrasse 21
D-79104 Freiburg
Germany
Phone: ++49-761-203-6036
Fax: ++49-761-203-8714
Email: Klaus.Piontek@ocbc.uni-freiburg.de
Web: http://www.chemie.uni-freiburg.de/orgbio/w3platt/

CCP4bb navigation

CCP4bb <-- 1999 <-- November 1999 <-- 30 November 1999

Previous message:
Subject: Re: Crystals grown from high ammonium sulphate
From: Savvas Savvides savvas {- dot -} savvides {- at -} UGENT {- dot -} BE
Date: 2008-11-04

Next message:
Subject: Re: tricoordinated ion?
From: Roger Rowlett rrowlett {- at -} MAIL {- dot -} COLGATE {- dot -} EDU
Date: 2008-11-04