[cctbxbb] crystal packing/unit cell question

Pavel Afonine pafonine at lbl.gov
Thu Nov 3 08:05:49 PDT 2011

> 1) isn't this a method of the X-ray structure object, not one of the 
> PDB objects?

expand_to_p1 is a method from xray/structure.py. I just used it yesterday.

> 2) won't it split up molecules to keep the sites all inside the unit cell?
> I'm getting annoyed that it's not easier to do this kind of lattice 
> generation for proteins, so I may just try coding it myself later 
> today or tomorrow.  (I'd like to figure out something analogous to the 
> 'symexp' function in PyMOL, but I think that's a little more work.)

I can't imagine what can be easier than this? If you don't want to 
"split" copies to be all atoms from 1 to -1, then I guess 
sites_mod_positive=True (or False, I don't remember) should probably 
simply multiply copies.
Anyway, it's faster to try than typing this email: try both, save 
xray_structure as PDB file and open it in PyMol.

What is 'symexp' function in PyMOL ?


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