Phenix includes TLS refinement which might explain the lower R values. Without TLS, Phenix and CNS should produce very similar R values. Are you using the latest version of CNS (1.21)?
A composite annealed omit map will be less model biased than standard sigmaA weight maps, but this is dependent on the particular case. Thus, it's useful to compute both types of maps. I don't see the need to compute a composite annealed omit map every time you make a change in model, though. Axel Brunger On Nov 15, 2008, at 10:34 AM, Priya Mudgal wrote:
Dear All, I have a general question for refinement using Phenix. Since the program gives much lower R/Rfree compared to CNS I am using it. My concern is, how model biased the 2fofc map is? After every refinement cycle it gives the mtz files corresponding to 2fofc and fofc maps. Is it alright to use that or do I have to calculate the composite omit map using CNS everytime. I am in my final stages of refinement now. My current R/Rfree is 25%/28%. Thanks for your suggestions. Regards, Priya -- Priya Mudgal PhD Student Duke University
Axel T. Brunger Investigator, Howard Hughes Medical Institute Professor of Molecular and Cellular Physiology Stanford University Web: http://atbweb.stanford.edu Email: [EMAIL PROTECTED] Phone: +1 650-736-1031 Fax: +1 650-745-1463
