[Pw_forum] Question about the PHonon example 15 calculation

[Paolo Giannozzi]

On Sun, 2015-01-11 at 19:29 -0700, Yi-Ping Huang wrote:

> When I start to run example 15, the Raman signal of CO2, I got the
> bending mode split into two different peaks. That confuses me. I
> though the two bending modes should be degenerate since the system
> should have axial symmetry along the O=C=O axis. 

the symmetry of a supercell containing a molecole may be lower than
the symmetry of the isolated molecule

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