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:CCP4BB@JISCMAIL.AC.UK] On Behalf Of Kenneth
A. Satyshur
Sent: Thursday, January 06, 2011 11:16 PM
To: CCP4BB@JISCMAIL.AC.UK
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
