Hi Tim The answer is a definite NO, the goal of refinement is to maximise the likelihood from the working set and the restraints. It is definitely not to optimise Rfree or LLfree. The correct value of the latter is whatever you get at convergence of refinement, i.e. at maximum of the likelihood, anything else is 'cheating'.
Cheers -- Ian On Wed, Aug 24, 2011 at 4:24 PM, Tim Gruene <t...@shelx.uni-ac.gwdg.de> wrote: > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > Dear all, > > especially at the beginning of model building and/or at low resolution > both Rfree and "-LL free" as reported in the refmac logfile show a > minimum at a some cycle before rising again. > > I am certainly not the only one tempted to first run refmac with a large > number of refinement cycles, determine that minimum and rerun refmac > with ncyc set to that minimum. > > Of course I want the resulting model and phases/map to be as close to > the what's in the crystal as possible in order to facilitate model > building. > > Is it therefore good practice to interrupt refmac wherever it finds a > minimum (if so, the minimum w.r.t. which number reported in the log-file)? > > Thanks for everyone's opinion and experience, > > Tim > > - -- > Dr Tim Gruene > Institut fuer anorganische Chemie > Tammannstr. 4 > D-37077 Goettingen > > GPG Key ID = A46BEE1A > > -----BEGIN PGP SIGNATURE----- > Version: GnuPG v1.4.11 (GNU/Linux) > Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ > > iD8DBQFOVReTUxlJ7aRr7hoRAqyzAKCZpMJPVSQJTDEoWGxZEymwvqfFcACeMNLL > rvIDPlXiL5HQmoNm7yrTt6k= > =UnKT > -----END PGP SIGNATURE----- >
