[Pw_forum] about phonon and structural optimization

[Paolo Giannozzi]

On Monday 11 July 2005 00:20, Eyvaz Isaev wrote:

> 2. You can calculate LO/TO splitting for semiconductors and
> insulators  using both dynmat.x and matdyn.x. The result will
> be the same. 

the logic is slightly different in the two cases: in dynmat.x
one diagonalises the dynamical matrix at q=0 and supplies 
the direction of q; in matdyn.x the direction of q is calculated 
from the list of q vectors at which the dynamical matrix is
diagonalised. This is explained in the headers of dynmat.f90 
and matdyn.f90, respectively

Paolo

-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
Piazza dei Cavalieri 7      I-56126 Pisa, Italy