Hi Elaine,

Thanks for getting back to me, I didn't realise it was as simple as that, though it turns out I may have been barking up the wrong tree somewhat.

I assumed more of the structures I was using had symmetry information than it appears they do, as they are EM resolved generally (and are C6 symmetrical).

I would expect I could achieve what I want with C6 symmetry, but as you can see in the images I've attached, the C6 symmetry is 'inside out', relative to the reference structure I'm trying to replicate. It looks like I need to specify a different axis of symmetry, but to also tell it to 'flip' how the molecules are being placed.

Here is my model in blue fitted well to a subunit of this structure (PDBID 1Y12)

I'm trying to replicate this donut shape, but it seems the model has no symmetry information I can use (sym #1 group #0 won't work , if #0 is the reference structure).

This is what I get from sym #1 group C6, hopefully you can understand what I'm getting at.

I've attached the model I'm trying to position if you have any thoughts about how to achieve this.

Hopefully there's a programmatic solution as I'll be intending to do this a number of times.

Many thanks - I hope I've explained myself clear enough!

Joe