[Pw_forum] Symmetry

[Stefano Baroni]

Do you mean the symmetry of the isolated molecule, or that of the crystal?

The symmetry group of the isolated molecule is the icosahedral group 
(Ih, 120 operations) and, as such, it is not the subgroup of any space 
group (the largest point group compatible with translations -- 
"crystallographic point group" -- is Oh, 48 operations). That's why 
QUASI-crystals are not crystals, and this is why PWscf (or any other 
code dealing with periodic systems, for what it matters) cannot identify 
all the symmetry operations of an icosahedrally symmetric system). See, 
e.g. http://mathworld.wolfram.com/CrystallographyRestriction.html

Hope this solve your doubts.

Yours, Stefano Baroni

Sergei Lisenkov wrote:
> Dear PWSCF users,
> 
> It is very strange, but PWscf does not find the any symmetry in fullerene C60. Why?
> 
> Thanks,
> Sergey
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