[Pw_forum] time for calculation of el-ph interactions of graphene supercell

[L.F.Huang]

Dear PWSCF developers and users:
  I am calculating a graphene supercell with one H atom one it, and I
take 4*4*1 size of supercell now, and there are 33 atoms with 32 C atoms
and 1 H atom. I calculate its phonon dispersions with 13 nodes with 2G
random memory for each node. When frequencies of one phonon mode are
calculated, the program enter into calculation of electron-phonon
interactions. But it has passed nearly 30 hours, and the calculation of
el-ph interaction still not completed! And for graphene unit cell with
2 C atoms, this process just costs about 10 seconds.
  I don't know it is normal that the calculation of el-ph interaction
of my graphene supercell costs so much or so much more time? Any one
has the experiences in the el-ph calculation of supercells? Could anyone
tell me how can I do or how much time I would expect to wait?

Thanks very much!
Best Wishes!

Yours Sincerely
L.F.Huang

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L.F.Huang(黄良锋) lfhuang at theory.issp.ac.cn
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 Add: Research Laboratory for Computational Materials Sciences,
      Instutue of Solid State Physics,the Chinese Academy of Sciences,
      P.O.Box 1129, Hefei 230031, P.R.China
 Tel: 86-551-5591464-328(office)
 Fax: 86-551-5591434
 Web: http://theory.issp.ac.cn (website of our theory group)
      http://www.issp.ac.cn    (website of our institute)
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