Dear 1009U, > I want to calculate the phonons at gamma point of the BZ. > 1) Do i need to make the supercell to find the phonons ?
No > is a unit cell is sufficient for it? Yes > 2) which unit cell i mean whether primitive or conventional unit should i > use? For whatever cell, you'll get Gamma phonons of the Brillouin zone corresponding to your unit cell. Meaning, the primitive cell will give you the minimal number of modes, whereas the conventional cell will add some extra modes from the zone boundary of the primitive folded onto q=0 of the now smaller Brillouin zone. Good luck Andrei Postnikov > with regards, > > 1009U >
