It depends to a large extent on the orientation of the Ncs operator. If that aligns with a crystal axis then there can be bias in the Rfree selection but if it doesn't NCS does not affect the Free R much ( in my opinion..) Eleanor
On 13 August 2014 09:14, Ed Pozharski <[email protected]> wrote: > By all means, try it both ways and see whether the R-Rfree gap narrows > with random vs thin shell selection. Depending on resolution and data > quality, you may also consider imposing NCS restraints. > > > Sent on a Sprint Samsung Galaxy S® III > > > -------- Original message -------- > From: Xianchi Dong > Date:08/12/2014 4:45 PM (GMT-05:00) > To: [email protected] > Subject: [ccp4bb] thin shell Rfree set selection > > Dear all, > I have a dataset of C2 symmetry and 2 molecules in the ASU. I am wondering > if I have to use thin shell Rfree set selection to avoid Rfree bias by NCS. > And which Rfree selection method is better? > > Thanks in advance. > > Xianchi >
