3D ab-Initio reconstruction: alignment issues

Hi,
I am attempting to reconstruct my highly symmetric protein. While 2D classification yielded nice results, I encountered an issue with unaligned initial ab-initio reconstruction. Any advice on how to address this?
(P.S. I usually enforce symmetry in the refinement process and obtain high-quality particles.)

2D classes:
image

3D ab-initio:

Yes - try disabling both real space recentering and enforcement of non-negativity. That pair of changes often helps mitigate this phenomenon in highly symmetric cases. If that doesn’t work, you can always enforce symmetry during ab initio.

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Disabling did not worked that well, but enforcing symmetry did! Thanks!

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Try to enforce symmetry during ab initio. And then use C1 for refinement. This workflow also works.

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