[phenixbb] Global refinement parameters - use statistical model for missing atoms

[Pavel Afonine]

  Hi Joe,

I added this option with a high expert level:

use_statistical_model_for_missing_atoms = False
       .type = bool
       .expert_level=2

so it's not too visible at the moment... I'm still working on it.

This will be a way to explicitly account for missing atoms in severely 
incomplete models. I will write a quick notice on phenixbb once it is 
available for general use.

Pavel.

> Hi All,
>
> Does it make sense that when the box for "use statistical model for 
> missing atoms" is picked under the GUI's "Global refinement parameters 
> options" that one might obtain "better" Free-R values? I seem to be 
> seeing that for a 2.3 A refinement of a crystal with a monomer of 550 
> residues in the asymmetric unit and 68% solvent content. When I 
> uncheck the box I get about a 3% increase in Free-R. Is there more 
> information about what this option is actually doing and when it might 
> be useful to employ?
>
> Joe