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question on phonon calculations

Elk Users
Elio
2015-02-20
2015-04-21
  • Elio

    Elio - 2015-02-20

    Dear all,

    I have a question about the dynamical matrices that Elk calculates for phonons. I am trying to reproduce the results for Al. I have taken a 24x24x24 k-grid and a 6x6x6 q grid. I know that there should be 48 irreducible representations but how many of these DYN_Qqqqq_qqqq_qqqq_Sss_Aaa_Pp.OUT should be? Is a 6x6x6 grid too dense? I am running calculations on 5 nodes each with 8 processors and till now only 15 of these matrices were done.

    Thank you

    Elio
    University of Rondonia
    Brazil

     
  • Elio

    Elio - 2015-02-20

    Discard my question about the DYN_; they are actually the Irreducible representations.
    Sorry for that

     
  • supermarche

    supermarche - 2015-04-07

    Hello Elio,

    I have to correct you in that point: DYN files are not irreps. They represent a specific row of the dynamical matrix, i. e. the force acting on all atoms with respect to a displacement in a supercell defined by qqqq_qqqq_qqqq of atom aa of species ss in direction p. Up to now, irreducible representations of phonon modes to reduce the computational complexity are not implemented, as far as I know.

    All the best,
    Marc

     
  • Elio

    Elio - 2015-04-21

    Dear Marc,

    Sorry for the late reply as I was on holidays. Thank you very much for correcting my information about the DYN. files

     

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