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

[Eduardo Ariel Menendez Proupin]

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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