Point group symmetry of a space group

[fislam]

Hi,

I am trying to find out the point group associated with the space group of a crystal. In the OUTCAR file, vasp writes the following:

"The static configuration has the point symmetry S_2 .
The point group associated with its full space group is C_2h.

The dynamic configuration has the point symmetry S_2 .
The point group associated with its full space group is C_2h."

I have checked the group table, which shows that the S_2 point group has two symmetry operators and C_2h has four symmetry operators. When I visualize the POSCAR file, I don't see any mirror plane.

I am wondering if anyone could please explain which point group I should consider to explain the results.


Thanks,
Fhokrul

[martin.schlipf]

I'm not clear what exactly you want to understand, so I'll give you two answers:

If you want to know how Vasp analysis the symmetry of the crystal, you will need to look into the following routines: symmetry.F, symlib.F, and lattlib.F. For the understanding it is important to note that Vasp will account for the symmetry breaking of velocities and magnetic moments, which may explain the results you are seeing.

If you want specific information about the system you are looking at, you can use one of the available online tools (findsym or the Bilbao crystallographic server to analyze it further. There are also some packages you can use like e.g. spglib.

[fislam]

Thanks for the reply. The link you sent are useful to see the symmetry operators.

Fhokrul