Right, the problem is that these three atoms form carboxyl group of Glu, and if I put them (I tried this option) in one occupancy constrained group, occupancies are  still refined individually with the sum between three atoms =1. From chemistry point of view I think carboxyl group leaves as one entity, so occupancy should be the same between all three atoms. Is there another way how to constrain it between three atoms if it is not the case of alt conformation?

Thank you




On Tue, Nov 20, 2012 at 2:27 PM, Nathaniel Echols <nechols@lbl.gov> wrote:
On Tue, Nov 20, 2012 at 3:29 AM, Mikalai Lapkouski <gort105@gmail.com> wrote:
I tried to set the occupancy for those atoms 0.8 and refine individually. But obviously occupancies for those atoms are individually refined to different values which I dont think is the right way. Is there a way of how to refine occupancies for those atoms so that they remain identical after refinement (say all have 0.6)?

I'm a little surprised that the atoms within a residue aren't already constrained to be the same occupancy, but that may only apply if they're labeled as an alternate conformer.  But I think all you need to do this is to define them as a constrained group, as described here:

https://www.phenix-online.org/version_docs/dev-1218/refinement.htm#anch111

(scroll down to Example 4 for the messy details.)  If you're using the GUI, you can find the relevant controls by selecting "Occupancy" from the menu labeled "Modify atom selections for" below the strategy choices.

-Nat

_______________________________________________
phenixbb mailing list
phenixbb@phenix-online.org
http://phenix-online.org/mailman/listinfo/phenixbb