[Pw_forum] q-points in the phonon calculations

[Elie M]

Dear all,
I am doing phonon calculations at the Dirac K point of a graphene allotrope and I am getting two negative frequencies (almost degenerate). I need to confirm something regarding the units of the q-points. Should they be in terms of b1, b2 and b3, the reciprocal lattice vectors or in cartesian coordinates in terms of 2Pi/a? Is this written somewhere in the Guide...

Reagrds
Elie Moukaesuniversity of NottinghamNG7 2RDUK
 		 	   		  
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