[Pw_forum] phonon dispersion calculations
Axel Kohlmeyer
akohlmey at cmm.upenn.edu
Tue Aug 8 14:36:40 CEST 2006
On 8/8/06, Tuhina Kelkar <tr.kelkar at ncl.res.in> wrote:
>
>
> Hi! I am a new user of QEspresso. I want to use it to calculate the phonon
hi,
you may want to take a look at the tutorial material that was put
up for the recent QE tutorials in minneapolis and urbana.
http://www.vlab.msi.umn.edu/events/lecture.shtml
http://mccweb1.mcc.uiuc.edu/software/display/ss2006/Quantum+Espresso+Lab
cheers,
axel.
> dispersion for MgH2 along the following high symmetry points: Gamma to X to
> M to Gamma to Z to R to A to Z.
>
> But I am not being able to construct the matdyn.in file. How does one decide
> on the number of q-points? And how to go about creating this list of
> q-points to be used in matdyn.in?
>
> I have already obtained the IFC's and the following is the resulting q2r.out
> file:
>
> reading grid info from file dyn0
> reading force constants from file dyn1
> Dielectric Tensor not found
> nqs= 1
> q= 0.00000000 0.00000000 0.00000000
> reading force constants from file dyn2
> nqs= 1
> q= 0.00000000 0.00000000 -0.74850299
> reading force constants from file dyn3
> nqs= 2
> q= 0.00000000 -0.50000000 0.00000000
> q= 0.50000000 0.00000000 0.00000000
> reading force constants from file dyn4
> nqs= 2
> q= 0.00000000 -0.50000000 -0.74850299
> q= 0.50000000 0.00000000 -0.74850299
> reading force constants from file dyn5
> nqs= 1
> q= -0.50000000 -0.50000000 0.00000000
> reading force constants from file dyn6
> nqs= 1
> q= -0.50000000 -0.50000000 -0.74850299
> q-space grid ok, #points = 8
>
> fft-check success (sum of imaginary terms < 10^-12)
>
> Thanks in advance.
> Tuhina
>
--
=======================================================================
Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu http://www.cmm.upenn.edu
Center for Molecular Modeling -- University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582, fax: 1-215-573-6233, office-tel: 1-215-898-5425
=======================================================================
If you make something idiot-proof, the universe creates a better idiot.
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