[Pw_forum] relaxation process stopped without reaching the convergence "Tengfei Cao"

[Chenghua Sun]

Hi TengFei,

You can reduce the conv_thr = 1.0d-8  (like 1.0d-3) and mixing_beta = 0.7 (how about 0.1 or 0.2) firstly and when it gets converged, you then improve it step by step.

Hopefully it works.

Chenghua
--------------------------------------------------------------------------------------
Chenghua Sun, PhD
ARC Centre of Excellence for Functional Nanomaterials
Centre for Computational Molecular Science
Australian Institute for Bioengineering and Nanotechnology,
AIBN Building 75, The University of Queensland
Qld 4072, Brisbane, Australia
Tel (617) 33463972;                Fax (617) 33463992
email: c.sun1 at uq.edu.au
---------------------------------------------------------------------------------------

________________________________
From: pw_forum-bounces at pwscf.org [pw_forum-bounces at pwscf.org] On Behalf Of 曹腾飞 [tfcao at theory.issp.ac.cn]
Sent: Monday, 28 March 2011 12:37 AM
To: pw_forum
Subject: [Pw_forum] relaxation process stopped without reaching the convergence "Tengfei Cao"

Dear QE users
I'm doing the relaxation calculation about graphene with hydrogen atoms absorbed on it .But for some configurations the calculation stopped by itself without achieving the convergence . I want to know what can be the reasons . What can I try to achieve the convergence .Any help will be greatly appreciated .Here is my input file:
&CONTROL
title = 'graphene layer' ,
calculation = 'relax' ,
restart_mode = 'restart' ,
outdir = './tmp' ,
pseudo_dir = '/lustre/ISSP2/tfcao/pseudo' ,
prefix = 'graphene' ,
nstep = 400 ,
/
&SYSTEM
ibrav = 8 ,
a = 12.31 , b = 12.79312342 , c = 12.000 ,
nat = 66 ,
ntyp = 2 ,
occupations = 'smearing' ,
tot_charge = 0.0,
nosym = .true. ,
degauss = 0.02 ,
smearing = 'mp' ,
nspin = 2 ,
starting_magnetization(1) = 0.9 ,
ecutwfc = 30.0 ,
ecutrho = 300.0 ,
/
&ELECTRONS
conv_thr = 1.0d-8 ,
mixing_mode = 'local-TF' ,
mixing_beta = 0.7 ,
diagonalization = 'david' ,
/
&IONS
/
ATOMIC_SPECIES
C 12.0107 C.pbe-rrkjus.UPF
H 1.0000 H.pbe-rrkjus.UPF
ATOMIC_POSITIONS crystal
C 0.0000000 0.0000000 0.50000000 0 0 0
C 0.10000000 5.55555671E-02 0.50000000
C 0.10000000 0.16666667 0.50000000
C 0.0000000 0.22222224 0.50000000
C 0.0000000 0.33333334 0.50000000
C 0.10000000 0.38888890 0.50000000
C 0.10000000 0.50000000 0.50000000
C 0.0000000 0.55555558 0.50000000
C 0.0000000 0.66666669 0.50000000
C 0.10000000 0.72222227 0.50000000
C 0.10000000 0.83333337 0.50000000
C 0.0000000 0.88888896 0.50000000
C 0.20000000 0.0000000 0.50000000
C 0.30000001 5.55555671E-02 0.50000000
C 0.30000001 0.16666667 0.50000000
C 0.20000000 0.22222224 0.50000000
C 0.20000000 0.33333334 0.50000000
C 0.30000001 0.38888890 0.50000000
C 0.30000001 0.50000000 0.50000000
C 0.20000000 0.55555558 0.50000000
C 0.20000000 0.66666669 0.50000000
C 0.30000001 0.72222227 0.50000000
C 0.30000001 0.83333337 0.50000000
C 0.20000000 0.88888896 0.50000000
C 0.40000001 0.0000000 0.50000000
C 0.50000000 5.55555671E-02 0.50000000
C 0.50000000 0.16666667 0.50000000
C 0.40000001 0.22222224 0.50000000
C 0.40000001 0.33333334 0.50000000
C 0.50000000 0.38888890 0.50000000
C 0.50000000 0.50000000 0.50000000
C 0.40000001 0.55555558 0.50000000
C 0.40000001 0.66666669 0.50000000
C 0.50000000 0.72222227 0.50000000
C 0.50000000 0.83333337 0.50000000
C 0.40000001 0.88888896 0.50000000
C 0.60000002 0.0000000 0.50000000
C 0.70000005 5.55555671E-02 0.50000000
C 0.70000005 0.16666667 0.50000000
C 0.60000002 0.22222224 0.50000000
C 0.60000002 0.33333334 0.50000000
C 0.70000005 0.38888890 0.50000000
C 0.70000005 0.50000000 0.50000000
C 0.60000002 0.55555558 0.50000000
C 0.60000002 0.66666669 0.50000000
C 0.70000005 0.72222227 0.50000000
C 0.70000005 0.83333337 0.50000000
C 0.60000002 0.88888896 0.50000000
C 0.80000001 0.0000000 0.50000000
C 0.90000004 5.55555671E-02 0.50000000
C 0.90000004 0.16666667 0.50000000
C 0.80000001 0.22222224 0.50000000
C 0.80000001 0.33333334 0.50000000
C 0.90000004 0.38888890 0.50000000
C 0.90000004 0.50000000 0.50000000
C 0.80000001 0.55555558 0.50000000
C 0.80000001 0.66666669 0.50000000
C 0.90000004 0.72222227 0.50000000
C 0.90000004 0.83333337 0.50000000
C 0.80000001 0.88888896 0.50000000
H 0.40000000 0.66666667 0.60000000
H 0.50000000 0.50000000 0.60000000
H 0.60000000 0.66666667 0.600000000
H 0.00000000 0.00000000 0.600000000
H 0.90000000 5.55555671E-02 0.600000000
H 0.00000000 0.88888889 0.6000000000
K_POINTS automatic
5 5 1 0 0 0
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