2012/1/6 Pete Meyer <pame...@mcw.edu>: > However, at 3.2 Angstroms I'd recommend against using atomic B-factors - > the "rule of thumb" for this is 2.8 Angstroms for atomic B-factors (or > at least it was back in the day). It might help to use an overall > B-factor combined with one (or a few) TLS groups.
This may be true for older software which restraints B-factors only to bonded atoms, but it is not the case in Phenix*, which takes into account all nearby atoms, not just bonded ones. The result is that individual B-factor refinement is very stable at low resolution - we don't know what the limit is, but it routinely works very well at 4A. Of course the performance is still dependent on solvent content, NCS, etc., but it is very rare that grouped B-factor refinement actually works better. -Nat * I think Refmac may do something similar, but I haven't tried this recently. I would be very surprised if it did not work well at 3.2A, however.
