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<div>Dear Elie Moujaes:
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The time cost for the calculation of dynamical matrix in your case is reasonable. Because DFPT needs to solve the perturbation KS equation iteratively for each reciprocal vector. In addition, why did not you specify the value of nq3 to be 1? Graphene is a monolayer of carbon atoms, nq3=1 is enough.
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To obtain decent phonon dispersion, maybe denser q grid be needed. And to calculate some thermodynamic functions accurately, maybe q grid denser than 9*9*1 is needed. May these be somewhat helpful.
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Best Wishes!
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Yours Sincerely
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L. F. Huang
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</FONT><FONT color=#444444>> From: Elie Moujaes
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</FONT><FONT color=#444444>> Subject: [Pw_forum] ph.x taking a lot of time to run!
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</FONT><FONT color=#444444>> To:
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</FONT><FONT color=#444444>> Message-ID:
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</FONT><FONT color=#444444>> Dear PWSCF users,
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> Hope you all had a happy Easter. I am running the ph.x code for graphene(and Thankfully no errors are encountered). it is just that it IS taking a really long time to produce the dynamical matrices on the q grid I specified which is:
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</FONT><FONT color=#444444>> nq1= 2, nq2=2, nq3=2 (a total of 8 points).. It is taking like an our to produce the .dyn files for every q point. I do not think it should require that much time. Is there something I might be missing?
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> Thank you
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> Elie Moujaes
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> University of Nottingham
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> NG7 2RD
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</FONT><FONT color=#444444>>
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</FONT><FONT color=#444444>> UK
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------
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======================================================================
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L.F.Huang(黄良锋) DFT and phonon physics
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======================================================================
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Add: Research Laboratory for Computational Materials Sciences,
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Instutue of Solid State Physics,the Chinese Academy of Sciences,
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P.O.Box 1129, Hefei 230031, P.R.China
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Tel: 86-551-5591464-328(office)
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Fax: 86-551-5591434
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Web: <A href=http://theory.issp.ac.cn target=_blank>http://theory.issp.ac.cn</A</FONT><FONT color=#444444>> (website of our theory group)
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<A href=http://www.issp.ac.cn target=_blank>http://www.issp.ac.cn</A</FONT><FONT color=#444444>> (website of our institute)
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