Hmm - there are some hydrogens which are simply not fixable from
chemistry, or electron density at low (ie <1.5A!) resolution - any of us
who have looked in vain for them can testify to that - and I cant think
that it is good to add in scatterers when you dont know where they are.
The ones determined uniquely I do include once the structure is as well
positioned as the experiment allows..
Eleanor
- On 01/07/2011 06:35 PM, Andrew T. Torelli wrote:
> Hi Kenneth,
>
> There are recognized advantages to including riding hydrogens during refinement, even at low resolution. Others have written on this better than I could (the following link is a post to the CCP4bb from the archives):
>
> http://www.ysbl.york.ac.uk/ccp4bb/2002/msg01215.html
>
> -Andy Torelli
>
> -----Original Message-----
> From: CCP4 bulletin board [mailto:[log in to unmask]] On Behalf Of Kenneth A. Satyshur
> Sent: Thursday, January 06, 2011 11:16 PM
> To: [log in to unmask]
> Subject: [ccp4bb] Do carbon scattering include hydrogen
>
> Persons of interest:
>
> I understood that refinements in refmac of low res structures without hydrogens includes a component of the Hydrogen atom attached to the carbon in the carbon scattering factors. Or is this just if the Hydrogen atoms
> are in the riding position. If so, why bother to add hydrogens in the riding position.
>
> Thanks
> kas
>
>
> --
> Kenneth A. Satyshur, M.S.,Ph.D.
> Associate Scientist
> University of Wisconsin
> Madison, Wisconsin 53706
> 608-215-5207
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