[Phonopy-users] QE+Phonopy - negative frequency in phonon dispersions of graphene

[Artur D. <adu...@wi...>]

Dear All,
I try to use QE and Phonopy software to calculate the phonon dispersiono
of graphene supercell (3x3). Unfortunately as a results I have negative
phonons frequencies. I try changed pseudopotentials and k-mesh but without
success.

Please find my input files as well as the output figure enclosed to this
email.

Do you have any suggestion how eliminate the negative phonons frequencies?

Thank you in advance for your help!

Your sincerely,
Artur Durajski
-- 
Assistant Professor
Institute of Physics
Czestochowa University of Technology
Ave. Armii Krajowej 19, 42-200 Czestochowa, Poland
e-mail: adu...@wi...
http://adurajski.wip.pcz.pl