[Pw_forum] a2Fq2r.*

[Hahnbidt Rhee]

Prof Isaev,

Thank you for your response. I am still confused, though. a2F is a function
of omega only, but the a2Fq2r.* files hold matrices, in the exact format of
the dynamical matrices. But these are not the dyn mats; separate files
called matdyn* (* ranging from 1 to number of q-points) are created, which
are the dyn mats. Another issue is that these a2Fq2r.* files are created
BEFORE the q2r calculation. q2r.x actually uses these files and creates the
files a2Fmatdyn.* (* ranging from 61 to 70). It seems to me like the
a2Fmatdyn.* are used for matdyn.x to get a2F(omega), so the a2Fq2r.*
files--and the a2Fmatdyn.* files, for that matter--couldn't possibly be the
spectral function data. Am I incorrect? Thank you for your time.

HB


On Thu, May 27, 2010 at 4:49 PM, Eyvaz Isaev <eyvaz_isaev at yahoo.com> wrote:

> Dear Rhee,
>
> --- On Fri, 5/28/10, Hahnbidt Rhee <hrhee at ucdavis.edu> wrote:
>
> > What exactly are in the files a2Fq2r.* (the suffix ranging from 51 to >
> 60), which are generated during an el-ph calculation?  The format of
> > these files are like those of the dynamical matrices, but they are not >
> the same.
>
> They are Eliashberg function (\alpha^2F(\omega)) calculated for 10 degauss
> (ranging from 0.005 till 0.05 by default) which are then used to evaluate
> lambda.
>
> > How are they related to the dynamical matrices?
>
> Not sure they are related.
>
> > Why are there 10 of them, and how are these related to each other?
>
> This one is due to double delta in the \gamma function which enters to the
> Eliashberg function. As integration of double delta is a hard problem, the
> summation in the BZ is performed by special points and broadening
> techniques. Different values for delta (10 by default) is used to find
> converged (w.r.t. delta) lambda.
>
> So, they are not related.
>
> Bests,
> Eyvaz.
>
> -------------------------------------------------------------------
> Prof. Eyvaz Isaev,
> Department of Physics, Chemistry, and Biology (IFM), Linkoping University,
> Sweden
> Theoretical Physics Department, Moscow State Institute of Steel & Alloys,
> Russia,
> isaev at ifm.liu.se, eyvaz_isaev at yahoo.com
>
>
>
>
>
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