FBEAUT and FCREF

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In BPV case, FBEAUT and FCREF are set to F (at final cycle). Do we need to use them at early cycle? Why turn them off in final cycle? Is it anything to do with Ewald correction or B (-80.0) factor?

It is probably best to turn off both FBEAUT and FCREF during the refinement and set them to T only for the last reconstruction. They are primarily meant to produce a properly filtered and nicely symmetrized final map. Symmetry is also applied when FBEAUT is set to F but because the application is done in reciprocal space it does not always show up correctly in real space. For example, a five-fold symmetry applied in reciprocal space will lead to small but visible symmetry deviations in real space, mainly due to interpolation artifacts. Therefore, to obtain a perfectly looking symmetry in real space, set FBEAUT to T.

In reply to by niko

The last refinement: Do you mean final stage of refinement or when we seperate refine and reconstruction during refinement and turn off during refine and turn on when reconstruction?