[Pw_forum] Three questions about phonon calculation

[yhho]

Dear all,
I have some questions about Phonon calculation.

1. If I use ph.x to run the graphene phonon dispersion and pdos,
    should I use the q points which is multiple of 6 because of the hexagonal shape of grathpene crystal?

2. When I run phonon-dispersion calculation, it always cost very long cpu time. Is that normal?

3. Can QE calculate vibration mode?
    How could I set terms in ph.in to get vibration mode? 
    And how could I plot the vibration mode from the output file?

Thanks a lot.

best regards,
Yu Han Ho

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