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Dear Ian,

"10.00A"  sounds very much like somebody used shelxpro to create an
ins-file from a PDB file and did not correct the SHEL card to include
low resolution data. So the data may well contain data at 84A, but shelx
does not use the data if the SHEL card is left at its default (10 0.1).

Cheers,
Tim

P.S.: "obvious" can be just a dangerous word as "trivial"...

On 10/27/2011 09:31 PM, Ian Tickle wrote:
> Hi, currently Refmac writes the wrong info for the low resolution
> cutoff, for example:
> 
> REMARK   3   PROGRAM     : REFMAC 5.6.0119
> REMARK   3  DATA USED IN REFINEMENT.
> REMARK   3   RESOLUTION RANGE HIGH (ANGSTROMS) :   1.00
> REMARK   3   RESOLUTION RANGE LOW  (ANGSTROMS) :  84.35
> 
> In contrast Shel-X puts in:
> 
> REMARK   3   RESOLUTION RANGE LOW  (ANGSTROMS) : 10.00
> 
> The mtzdump of the MTZ file shows:
> 
>    1 NONE   -83       0      0  100.00    -27.0     27.0  84.35   1.00   H  H
>    2 NONE     0      97      0  100.00     54.9     54.9  84.35   1.00   H  K
>    3 ASC      0      83      0  100.00     31.0     31.0  84.35   1.00   H  L
>    4 NONE    0.0     1.0     0  100.00     0.95     0.95  84.35   1.00   I  
> FREE
>    5 NONE    0.0  2071.8   435   99.82   125.22   125.22  10.00   1.00   F  FP
>    6 NONE    0.9    90.0   435   99.82     2.73     2.73  10.00   1.00
>   Q  SIGFP
> 
> So obviously what has happened is that the Free R flags have been
> generated to the high resolution cutoff and the low-res reflections,
> i.e. below 10 Ang only have HKL & FREE defined.  Somewhere along the
> line (this is data from the PDB) the low-res F's were lost.  So IMO
> one cannot claim that these data were "used" in refinement.  Getting
> tthe low-res cutoff wrong has a big effect on the electron density
> that one expects for a given resolution range!  It seems to me that it
> would be preferable to omit information rather than risk putting in
> the wrong value, at least then one would know to go find the info
> somewhere else.
> 
> Cheers
> 
> -- Ian
> 

- -- 
- --
Dr Tim Gruene
Institut fuer anorganische Chemie
Tammannstr. 4
D-37077 Goettingen

GPG Key ID = A46BEE1A

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