Hi Yuri, virtually any map computed using model phases is model biased. 2mFo-DFc map computed with m and D estimated using "free" reflections is less model biased than (Fobs, PHIcalc). See R.Read (1986). Iterative-build OMIT maps seem to be the least model biased: *Iterative-build OMIT maps: map improvement by iterative model building and refinement without model bias.*T. C. Terwilliger, R. W. Grosse-Kunstleve, P. V. Afonine, N. W. Moriarty, P. D. Adams, R. J. Read, P. H. Zwart and L.-W. Hung/Acta Cryst./*D64*, 515-524 (2008) http://www.iucr.org/cgi-bin/paper?wd5088 Pavel On 9/21/11 4:07 PM, Yuri wrote:
I was having a discussion with a friend about maps and model bias. Is the Fobs/PHImodel more biased than 2FOFCWT/PHI2FOFCWt? What about an omit region of these two? Thanks for any opinion on this