[Pw_forum] convergence NOT achieved after 100 iterations: stopping

[GAO Zhe]

How about trying to fix the movement for BN-sheet and just move H atoms. The BN-sheet may achieve a concavity during "relax" process. For the absorption of H2, the concavity will vanish and a plane-BN finally be obtained. But for single H atom, I am not sure whether one can ignore such an effect.
By the way, is it reasonable that only one H atom was absorped instead of diatom H2 molecule?


--
GAO Zhe
CMC Lab, Materials Science & Engineering Department,
Seoul National University, South Korea
 

At 2012-04-27 09:20:20,"Cao TF" <tfcao at theory.issp.ac.cn> wrote:

Dear QE users
Recently, I have done some calculation of BN sheet with hydrogen atoms adsorbed on it. The problem is that when I let hydrogen atoms adsorb on the N atoms. The calculation is hard to converge. Although, I have changed mixing_beta and the number of K points. The problem have not been solved. Dose anyone have some experience on such kind of calculations? Any suggestions 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' ,
tprnfor = .TRUE. ,
nstep = 400 ,
/
&SYSTEM
ibrav = 8 ,
a = 15.026832 , b = 13.014 , c = 15.0 ,
nat = 74 ,
ntyp = 3 ,
starting_magnetization(1) = 0.5 ,
occupations = 'smearing' ,
nosym = .TRUE. ,
degauss = 0.005 ,
smearing = 'mp' ,
nspin = 2 ,
ecutwfc = 30.0 ,
ecutrho = 300.0 ,
/
&ELECTRONS
conv_thr = 1.0d-7 ,
mixing_mode = 'local-TF' ,
mixing_beta = 0.1 ,
diagonalization = 'cg' ,
/
&IONS
ion_dynamics = 'bfgs' ,
pot_extrapolation = 'atomic' ,

/
ATOMIC_SPECIES
B 10.811 B.pbe-n-van.UPF
N 14.00674 N.pbe-rrkjus.UPF
H 1.00000 H.pbe-rrkjus.UPF
ATOMIC_POSITIONS crystal
ATOMIC_POSITIONS crystal
N 0.0000000 0.0000000 0.50000000 0 0 0
B 0.0000000 0.11111100 0.50000000
N 8.33330005E-02 0.16666700 0.50000000
B 8.33330005E-02 0.27777800 0.50000000
N 0.0000000 0.33333299 0.50000000
B 0.0000000 0.44444400 0.50000000
N 8.33330005E-02 0.50000000 0.50000000
B 8.33330005E-02 0.61111099 0.50000000
N 0.0000000 0.66666597 0.50000000
B 0.0000000 0.77777696 0.50000000
N 8.33330005E-02 0.83333296 0.50000000
B 8.33330005E-02 0.94444394 0.50000000
N 0.16666700 0.0000000 0.50000000
B 0.16666700 0.11111100 0.50000000
N 0.25000000 0.16666700 0.50000000
B 0.25000000 0.27777800 0.50000000
N 0.16666700 0.33333299 0.50000000
B 0.16666700 0.44444400 0.50000000
N 0.25000000 0.50000000 0.50000000
B 0.25000000 0.61111099 0.50000000
N 0.16666700 0.66666597 0.50000000
B 0.16666700 0.77777696 0.50000000
N 0.25000000 0.83333296 0.50000000
B 0.25000000 0.94444394 0.50000000
N 0.33333400 0.0000000 0.50000000
B 0.33333400 0.11111100 0.50000000
N 0.41666698 0.16666700 0.50000000
B 0.41666698 0.27777800 0.50000000
N 0.33333400 0.33333299 0.50000000
B 0.33333400 0.44444400 0.50000000
N 0.41666698 0.50000000 0.50000000
B 0.41666698 0.61111099 0.50000000
N 0.33333400 0.66666597 0.50000000
B 0.33333400 0.77777696 0.50000000
N 0.41666698 0.83333296 0.50000000
B 0.41666698 0.94444394 0.50000000
N 0.50000101 0.0000000 0.50000000
B 0.50000101 0.11111100 0.50000000
N 0.58333403 0.16666700 0.50000000
B 0.58333403 0.27777800 0.50000000
N 0.50000101 0.33333299 0.50000000
B 0.50000101 0.44444400 0.50000000
N 0.58333403 0.50000000 0.50000000
B 0.58333403 0.61111099 0.50000000
N 0.50000101 0.66666597 0.50000000
B 0.50000101 0.77777696 0.50000000
N 0.58333403 0.83333296 0.50000000
B 0.58333403 0.94444394 0.50000000
N 0.66666800 0.0000000 0.50000000
B 0.66666800 0.11111100 0.50000000
N 0.75000101 0.16666700 0.50000000
B 0.75000101 0.27777800 0.50000000
N 0.66666800 0.33333299 0.50000000
B 0.66666800 0.44444400 0.50000000
N 0.75000101 0.50000000 0.50000000
B 0.75000101 0.61111099 0.50000000
N 0.66666800 0.66666597 0.50000000
B 0.66666800 0.77777696 0.50000000
N 0.75000101 0.83333296 0.50000000
B 0.75000101 0.94444394 0.50000000
N 0.83333498 0.0000000 0.50000000
B 0.83333498 0.11111100 0.50000000
N 0.91666800 0.16666700 0.50000000
B 0.91666800 0.27777800 0.50000000
N 0.83333498 0.33333299 0.50000000
B 0.83333498 0.44444400 0.50000000
N 0.91666800 0.50000000 0.50000000
B 0.91666800 0.61111099 0.50000000
N 0.83333498 0.66666597 0.50000000
B 0.83333498 0.77777696 0.50000000
N 0.91666800 0.83333296 0.50000000
B 0.91666800 0.94444394 0.50000000
H 0.50000000 0.66666600 0.56900670
H 0.66666800 0.33333300 0.56900670
K_POINTS {automatic}
8 8 1 0 0 0
======================================================================
Teng Fei Cao
======================================================================
Research Laboratory for Computational Materials Sciences,
Instutue of Solid State Physics,the Chinese Academy of Sciences,
P.O.Box 1129, Hefei 230031, P.R.China
Tel: 86-551-5591464-326(office)
Fax: 86-551-5591434
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