Well - I am not sure whether this has anything to do with twin refinement but resolution limits are often a bit iffy. First the low resolution discrepancy. The Free R is generated to a lower and higher resolution than any observation. The FreeR set is meant to be complete for any possible index regardless of whether there IS an observation or not. (There are good reasons for this - if your data set is very incomplete it is better to have "reflections" included in map calculations with values DFc rather than omitting them altogether - ie effectively using them with intensity set to zero.) But it does look a bit bizarre in the printed limits.. I dont think it matters - the number of observations is not changed.
However for twin refinement things are a bit more complicated. Every "reflection" is actually a sum of two (or more) overlapping observations, I (h k l) and I(h(twin) k(twin) l(twin) ) and I really do not know what REFMAC will do if one of the pair is not observed.. And there are even more complicated scenarios if your twin is non-merahedral! Eleanor On Mon, 29 Mar 2021 at 08:21, Yuji Kado <[email protected]> wrote: > When I use refmac restrained refinement with intensity based twin > refinement, > resolution limit has been changed from 71.4519- 1.9996 to 47.392-1.986. > > From Log file, before refinement, Scaling and SigmaA resln: 71.4519 > 1.9996, seems to be correct. > But in the middle of log file, around Fom and SigmaA vs resolution, > Resolution limits are from 47.392 to 1.986. > > Output mtz file also shows different resolution range 71.46-1.925. > Amplitude based twin refinement is also failed. > Even if I input resolution range at Refinement parameters in refmac, the > problem still occurs. > > I also read someone's similar problem, but it has been solved because of > the update of refmac. > What should I do to correspond with resolution range between the output of > aimless and refmac restrained refinement? > > regards, > Yuji > > ######################################################################## > > To unsubscribe from the CCP4BB list, click the following link: > https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 > > This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a > mailing list hosted by www.jiscmail.ac.uk, terms & conditions are > available at https://www.jiscmail.ac.uk/policyandsecurity/ > ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/WA-JISC.exe?SUBED1=CCP4BB&A=1 This message was issued to members of www.jiscmail.ac.uk/CCP4BB, a mailing list hosted by www.jiscmail.ac.uk, terms & conditions are available at https://www.jiscmail.ac.uk/policyandsecurity/
