Local refinement - apply helical symmetry?


Local refinement currently has an option to apply point group symmetry - it might be useful to also have an option to apply helical symmetry as well.

Currently one can perform symmetry expansion after helical refinement and then locally refine in C1, but this is (1) not quite the same as applying symmetry to the reference during refinement and (2) very slow, as the particle count is inflated a lot during symmetry expansion.

Would also be very nice to have sym relaxation in local refinement, for both point group and helical symmetries :slight_smile:



Would appreciate this addition as well! :slight_smile:

Hi all,

Thanks for the feature request. This makes sense; the workaround is not quite the same but also much slower. Right now the reason we don’t have this is because local refinement includes various tweaks to handle peculiarities when masking out a small region of the protein, and helical refinement includes tweaks to handle peculiarities of filaments. Combining them both would be possible, but also would introduce a bit of code bloat – could we get an idea as to the possible use case and benefits of this?