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Re: [ccp4bb]: aniso scal
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Joe Brunzelle wrote:
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> Hello,
> This question pertains to refmac and aniso scaling. How do you turn
> off aniso scaling? I want to do to eliminate contributions from Ucryst (
> Uoverall = Ucryst + Utls + Utorsion + Uatom); if I'm not mistaken shelx
> doesn't do a Ucryst correction. I have been working a 1.1A refinement in
> both refmac and shelx and when I do an ortep drawing of the molecule from
> the two different programs, the shelx ADPs result in a more elliptical
> shape when compared to the refmac refine model. I've altered the Bfac
> parameters in refmac but I'm not seeing any significant changes to the
> ADPs.
> Has anybody looked at how the bfac params compare to simu values in
> shelx? Also, in some of the refmac examples there is reference to allow
> the geometry to be relaxed for hi res. struc. (i.e. weight matrix 40/50).
> What types of geo. values are being reported for these relaxed weights?
>
> Thank you in advance
To turn off aniso scaling you give
SCALE LSSCale ISOTropic
Then program should turn off aniso scaling
One more reason for smaller ellipticity could be SPHEricity restraint. You can relax
it using
SPHEricity <value>
Larger value means less spehericity. Default is 2. I use usually 5.
WEIGHT keyword concerns thermal and positional parameters.
Regards
Garib
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Garib N. Murshudov, Chemistry Department, University of York, U.K.
Tel: Home +44 (1904) 42 62 87, work: +44 (1904) 43 25 65
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