I can help if share ,, no problem.
Regards
Umer
On Fri, Jun 4, 2021, 7:39 PM Harry Powell - CCP4BB <
193323b1e616-dmarc-requ...@jiscmail.ac.uk> wrote:
> I’d have to say that Phil is possibly one of the small molecule
> crystallographers who could probably sort this out in a flash - hence my
>
I’d have to say that Phil is possibly one of the small molecule
crystallographers who could probably sort this out in a flash - hence my last
suggestion…
Harry
> On 4 Jun 2021, at 14:40, Phil Jeffrey wrote:
>
> Unlike macromolecular crystallography, small molecule crystallography is
> infreq
Twinning disorders solvent and hydrogen atoms position with adjustment of
several factors, small molecules are no so complicated as macromolecules.
Regards
Umer
On Fri, Jun 4, 2021, 6:41 PM Phil Jeffrey wrote:
> Unlike macromolecular crystallography, small molecule crystallography is
> infrequen
Unlike macromolecular crystallography, small molecule crystallography is
infrequently starved for data. So it makes no sense at all to extend
your data to e.g. I/sigI of 1.0 amd Rmeas > 80% unless you want your R1
to be >10% for no good reason or utility, which is what was behind my
suggestion
Hi
Yes, ANIS and adding hydrogens (in SHELXL) are good things to do - with 0.8Å
data most small molecule crystallographers would do this as a first step after
fitting all the non-H atoms.
One thing I can’t agree with is to cut the resolution of your data _unless_ you
have a very, very good rea
Agreed, ANIS is the command to try.
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Original Message
On 3 Jun 2021, 20:18, Philip D. Jeffrey wrote:
> R1 of 17% is bad for small molecule.
> 0.8 Å is in the eye of the beholder - if you're using macromolecular cutoffs
> then these might be too aggre
Hi Jacob,
>>The systematic absences in the hkl file pointed to P212121 being the
space group, which is what it was processed in.
If the data were processed in this space group (Laue class), the analysis
of the systematic absence won't tell anything else. Probably, it would be
more useful to proces
The systematic absences in the hkl file pointed to P212121 being the space
group, which is what it was processed in. As for the peaks, the highest peaks
are 3.92 at 2.72 A from an oxygen (Q1), 3.67 at 2.74 A from an oxygen (Q2), and
2.68 at 2.75 A from an oxygen (Q3). Q1 and Q3 seem to be about
R1 of 17% is bad for small molecule.
0.8 Å is in the eye of the beholder - if you're using macromolecular cutoffs
then these might be too aggressive for small molecule-type refinement stats -
try a more conservative cutoff lie 0.9 and see how that changes R1. However I
suspect it's more to do w
Dear Jacob,
An R-value of 17% is indeed suspiciously high for a small molecule structure.
Some thoughts:
Are you sure the space group is correct?
There might be twinning involved,. Have you checked the ’signs of twinning’ for
small molecules?
There might be disordered solvent molecules, which
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