[QE-users] Optimization does not converge

dv009200 at fh-muenster.de dv009200 at fh-muenster.de
Thu Apr 4 14:18:15 CEST 2019


I'm not sure but I think it has to do with the fact that you have an
unpaired electron in your system. You haven't defined the tot_charge of
your system, therefor the default value of tot_charge=0 means that you
have an OH radical adsorbed/bonded to the graphene layer. If that's what
you want you should specify nspin and tot_magnetization. If you want
instead a hydroxy-ion (OH-) adsorbed on to the graphene layer you should
set the tot_charge=-1.

But as I said I'm not sure about this, so maybe there are some other
suggestions from users with more experience in this area of expertise?

Best Regards

Dominik

M.Sc. Dominik Voigt PhD Student
Münster University of Applied Sciences
Email: dv009200 at fh-muenster.de


> Dear QE users,
> I am trying to optimize a single-layer graphene connected to a hydroxyl
> group.After 48 scf cycles,the optimization result has never reached the
> convergence value,the force of some atoms is always greater than the
> convergence threshold.But when I connect an epoxy group instead of a
> hydroxyl group on the graphene sheet, the optimization can reach
> convergence after 24 scf cycles.Does anyone know the reason for this?
> Any suggestions would be greatly appreciated.
> Thank you.
>
>
>  &control
>     calculation  = 'relax',
>     prefix='QJ1GO',
>     pseudo_dir = '/public/home/duan1/GuiWei/pseudo/',
>     outdir='/public/home/duan1/GuiWei/tempdir/'
>     tstress = .true.
>     tprnfor = .true.
>     etot_conv_thr=1.0D-4
>     forc_conv_thr=1.0D-3
> /
>  &system
>     ibrav= 0,
>     nat=66,
>     ntyp=3,
>
>     occupations='smearing',
>     smearing='mp',
>     degauss=0.02,
>
>
>     ecutwfc =40.0
>     ecutrho =320.0
>
>     vdw_corr='DFT-D'
>     london_s6 = 0.75
>
>
> /
> &electrons
>     conv_thr =  1.0d-8
>     mixing_beta = 0.2
>     mixing_mode = 'local-TF'
>     mixing_ndim=16
>     electron_maxstep=200
> /
> &IONS
>   ion_dynamics='bfgs'
> /
> CELL_PARAMETERS angstrom
> 19.680000000000003       0.000000000000010       0.000000000000000
>  0.000000000000000       8.521689973238882       0.000000000000000
>  0.000000000000000       0.000000000000000      25.000000000000000
> ATOMIC_SPECIES
> C  12.0107   C.pbe-rrkjus.UPF
> O   16.00    O.pbe-rrkjus.UPF
> H   1.00     H.pbe-rrkjus.UPF
> ATOMIC_POSITIONS  crystal
>   C   0.0000000000000000   0.0000000000000000   0.2164000000000000
>   C   0.1250000000000000  -0.0000000000000000   0.2164000000000000
>   C   0.0625000000000000   0.2499999999999999   0.2164000000000000
>   C   0.0000000000000000   0.4999999999999999   0.2164000000000000
>   C   0.2500000000000000  -0.0000000000000002   0.2164000000000000
>   C   0.1875000000000000   0.2499999999999999   0.2164000000000000
>   C   0.1250000000000000   0.4999999999999998   0.2164000000000000
>   C   0.0624999999999998   0.7499999999999989   0.2164000000000000
>   C   0.3750000000000000  -0.0000000000000002   0.2164000000000000
>   C   0.3125000000000000   0.2500000000000000   0.2164000000000000
>   C   0.2500000000000000   0.4999999999999999   0.2164000000000000
>   C   0.1875000000000000   0.7499999999999989   0.2164000000000000
>   C   0.5000000000000000  -0.0000000000000002   0.2164000000000000
>   C   0.4375000000000000   0.2500000000000000   0.2164000000000000
>   C   0.3750000000000000   0.4999999999999999   0.2164000000000000
>   C   0.3125000000000000   0.7499999999999988   0.2164000000000000
>   C   0.6250000000000000  -0.0000000000000004   0.2164000000000000
>   C   0.5625000000000000   0.2500000000000000   0.2164000000000000
>   C   0.5000000000000000   0.4999999999999999   0.2164000000000000
>   C   0.4375000000000000   0.7499999999999988   0.2164000000000000
>   C   0.7500000000000000  -0.0000000000000004   0.2164000000000000
>   C   0.6875000000000000   0.2499999999999999   0.2164000000000000
>   C   0.6250000000000000   0.4999999999999999   0.2164000000000000
>   C   0.5625000000000000   0.7499999999999988   0.2164000000000000
>   C   0.8750000000000000  -0.0000000000000004   0.2164000000000000
>   C   0.8125000000000000   0.2499999999999990   0.2164000000000000
>   C   0.7500000000000000   0.4999999999999999   0.2164000000000000
>   C   0.6875000000000000   0.7499999999999989   0.2164000000000000
>   C   0.9375000000000000   0.2499999999999990   0.2164000000000000
>   C   0.8750000000000000   0.5000000000000000   0.2164000000000000
>   C   0.8125000000000000   0.7499999999999988   0.2164000000000000
>   C   0.9375000000000000   0.7499999999999988   0.2164000000000000
>   C   0.0624999725702591   0.0833332967603452   0.2164000000000000
>   C  -0.0000000274297411   0.3333332967603450   0.2164000000000000
>   C   0.1874999725702590   0.0833332967603452   0.2164000000000000
>   C   0.1249999725702590   0.3333332967603450   0.2164000000000000
>   C   0.0624999725702589   0.5833332967603438   0.2164000000000000
>   C  -0.0000000274297409   0.8333332967603447   0.2164000000000000
>   C   0.3124999725702590   0.0833332967603452   0.2164000000000000
>   C   0.2499999725702590   0.3333332967603450   0.2164000000000000
>   C   0.1874999725702590   0.5833332967603448   0.2164000000000000
>   C   0.1249999725702590   0.8333332967603447   0.2164000000000000
>   C   0.4374999725702590   0.0833332967603452   0.2164000000000000
>   C   0.3749999725702590   0.3333332967603450   0.2164000000000000
>   C   0.3124999725702590   0.5833332967603448   0.2164000000000000
>   C   0.2499999725702590   0.8333332967603447   0.2164000000000000
>   C   0.5624999725702590   0.0833332967603451   0.2164000000000000
>   C   0.4999999725702591   0.3333332967603449   0.2164000000000000
>   C   0.4374999725702590   0.5833332967603438   0.2164000000000000
>   C   0.3749999725702590   0.8333332967603447   0.2164000000000000
>   C   0.6874999725702590   0.0833332967603451   0.2164000000000000
>   C   0.6249999725702590   0.3333332967603450   0.2164000000000000
>   C   0.5624999725702590   0.5833332967603447   0.2164000000000000
>   C   0.4999999725702591   0.8333332967603448   0.2164000000000000
>   C   0.8124999725702590   0.0833332967603451   0.2164000000000000
>   C   0.7499999725702590   0.3333332967603450   0.2164000000000000
>   C   0.6874999725702600   0.5833332967603440   0.2164000000000000
>   C   0.6249999725702590   0.8333332967603438   0.2164000000000000
>   C   0.9374999725702590   0.0833332967603450   0.2164000000000000
>   C   0.8749999725702590   0.3333332967603450   0.2164000000000000
>   C   0.8124999725702600   0.5833332967603438   0.2164000000000000
>   C   0.7499999725702590   0.8333332967603438   0.2164000000000000
>   C   0.9374999725702590   0.5833332967603438   0.2164000000000000
>   C   0.8749999725702601   0.8333332967603448   0.2164000000000000
>   O   0.5008325506691220   0.4975899051684459   0.2743438844378600
>   H   0.4505865611121930   0.4983293698599460   0.2875531708238770
> K_POINTS automatic
> 2  2  1  0  0  0
>
>
> Wei gui
> School of Mechanical Engineering?Chongqing University, China
>
>
>
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