There happened to be a nice discussion of that over on Darwin Central...
IIRC, one of the posters pointed out that the ice helix formed at -9 Farenheit and 40,000 atmospheres.
Too warm and too crowed for space.
...oh, and the ice was encased within carbon nanotubes.
Smells like polywater, redux.
Cheers!
On the other hand these guys gave detailed instructions and presumably others will be able to replicate, or debunk, the results they found.