[Pw_forum] Fwd: ABOUT POINT GROUP OF (Pnma) STRUCTURE

[Paolo Giannozzi]

On Mon, 2014-07-21 at 21:29 +0530, B D SAHOO wrote:

> why i am not finding the correct mode symmetry of pnma structure of
> Sb2Se3 compound by calculating the phonon at gamma point.as it is a
> orthorhombic structure  so it should show D2h_(mmm) but it is showing
> as C2h(2/m)

the scf calculation finds 4 symmetries. Is this what you expect? 
if not, see here:
http://www.quantum-espresso.org/wp-content/uploads/Doc/pw_user_guide/node19.html#SECTION000600190000000000000

P.

-- 
 Paolo Giannozzi, Dept. Chemistry&Physics&Environment, 
 Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
 Phone +39-0432-558216, fax +39-0432-558222