Dear colleagues, I am in the process of refining a P2(1) structure that is marked by Scala as twinned (L-test etc.) with a twinning fraction of ca. 0.2. I am still working on the twinning problem, so no more details about this. But what puzzles me right now is that, if I feed the data with a max. resolution of 1.95 A into Refmac with the "twin" refinement option on, it recognizes the resolution cut-off at first, but then uses a new cut-off of 1.88 A in the first ( and all subsequent) refinement cycles. Since there are no data at this resolution, this seems to screw up the calculation of R-values at high resolution and it reports for them zero-values in the co-ordinate header. Without twin refinement, the max. resolution stays at 1.95 A (but the final stats are worse, of course).
Is this a bug or am I missing here something? Thanks in advance, and I am happy to send log files or my precious data if necessary. Cheers, Uli --------------------------------------------------------------------------- dr ulrich gohlke staff scientist - macromolecular structure and interaction max-delbrück-center for molecular medicine (mdc) +49 30 9406 - 2725 (w) +49 30 9406 - 2548 (fax) [email protected]<mailto:[email protected]> http://www.mdc-berlin.de/en/research/research_teams/macromolecular_structure_and_interaction/
