[Pw_forum] Small value of stress at equilibrium (T=0,P=0)

[bramha pandey]

Thank you Eduardo Menendez Proupin Sir..
i have fixed it with meaningful results with your help.
 thanks once again to you and all pw users.

On Thu, Mar 22, 2012 at 7:19 PM, Eduardo Ariel Menendez Proupin <
eariel99 at gmail.com> wrote:

> Relax again from the last structure and you should get smaller residual
> stress. Otherwise, increase the cutoffs.
> Please, read this
>
> http://www.quantum-espresso.org/wiki/index.php/Methodological_Background#Stress
>
> Stress smaller than 10 kbar in a solid generally have little effect.
>
> Eduardo Menendez Proupin
> Departamento de Química Fisica Aplicada
> Facultad de Ciencias
> Universidad Autónoma de Madrid
> 28049 Madrid, Spain
> Phone: +34 91 497 6706
>
>
>
> ---------- Mensaje reenviado ----------
> From: bramha pandey <pandey.bramha at gmail.com>
> To: PWSCF Forum <pw_forum at pwscf.org>
> Cc:
> Date: Thu, 22 Mar 2012 19:08:56 +0530
> Subject: [Pw_forum] Small value of stress at equilibrium (T=0,P=0)
>
> Dear all,
> I am using AlN with zincblede structure using USPP (PBE xc).
> After completing convergence test of ecut and k-point, i calculated the
> equilibrium lattice constant(at T=0, P=0).
> But i wondered if i put this equilibrium lattice constant in calculation i
> got, small value of stress(-7.36kbar).
> i know this is Pulay stress and think it may be zero (may be i am wrong if
> so please correct me) at equilibrium but here it is not the case.
> i want to know whether this will affect the other property like bulk
> modulus, lattice constant calculation etc at different pressure and
> temperature.
> How can i fix it.
> Your valuable comment is highly aappriciable.
>
> --
> Thanks and Regards
> Bramha Prasad Pandey
> GLA University, Mathura.
> INDIA.
>
> --
>
>
>
>
>
>
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-- 
Thanks and Regards
Bramha Prasad Pandey
GLA University, Mathura.
INDIA.
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