[Pw_forum] Strange values of Tc

Isaiah Moses imoses87 at gmail.com
Fri Jul 28 16:06:29 CEST 2017


Yes Dr Giovanni.

We're working on that.

I appreciate your time,
Isaiah

On Fri, Jul 28, 2017 at 1:34 PM, Giovanni Cantele <
giovanni.cantele at spin.cnr.it> wrote:

> I’m not an expert about el-ph calculations. However, if it were a
> calculation made by myself,
> I would never trust Tc values obtained after modifying by hand lambda.f90,
> even if they were perfectly reasonable.
>
> el-ph calculations for sure require extremely  well converged electron
> calculations as well as well extremely well converged phonon
> calculations. So I would go through the phonon calculation, understand why
> there are negative frequencies and,
> even once you have obtained all positive frequencies, understand whether
> or not they are converged.
>
> Giovanni
>
>
> On 28 Jul 2017, at 13:26, Isaiah Moses <imoses87 at gmail.com> wrote:
>
> Thanks a lot, Dr Giovanni.
> I appreciate your response.
> We observed few values of frequencies to be negative.
> Matdyn1 has few more with others having either the first or the first 2/3
> to be negative.
> We set those to be zero, modifying lambda.f90 code.
>
> Could that be the problem?
>
> I've attached the input/output for lambda.x execution. Also matdyn1.
>
> There are 62-points and 33 irreps.
> I appreciate your time.
>
> --
> Isaiah Abu Moses
> Graduate Student,
> Physics Department,
> University of Ibadan,
> Nigeria
> <CyanoPh_lambda.in><CyanoPh_lambda.out><matdyn1>__________
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>
> --
>
> Giovanni Cantele, PhD
> CNR-SPIN
> c/o Dipartimento di Fisica
> Universita' di Napoli "Federico II"
> Complesso Universitario M. S. Angelo - Ed. 6
> Via Cintia, I-80126, Napoli, Italy
> e-mail: giovanni.cantele at spin.cnr.it
> Phone: +39 081 676910
> Skype contact: giocan74
>
> ResearcherID: http://www.researcherid.com/rid/A-1951-2009
> Web page: http://people.fisica.unina.it/~cantele
>
>
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-- 
Isaiah Abu Moses
Graduate Student,
Physics Department,
University of Ibadan,
Nigeria
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