[Pw_forum] optimization problems of vanadium oxide

WANG YUANQING yuanqing.wang at riken.jp
Tue Jan 17 10:33:24 CET 2017


Dear Manu,

Hi. Sorry for the late reply. I tried your settings (cov_thr and bfgs), however, it does not help. The force is still very large during relaxation. I found two oxygens tend to approach potassium very closely during relaxation, which is not reasonable.

Besides, I want to move the atoms in all directions. Is there anyone who can suggest me some alternative methods? Thank you in advance!

Best,

Yuanqing

 
Date: Thu, 5 Jan 2017 12:42:07 -0500
From: Manu Hegde <mhegde at uwaterloo.ca>
Subject: Re: [Pw_forum] optimization problems of vanadium oxide
To: PWSCF Forum <pw_forum at pwscf.org>
Message-ID:
        <CA+g44Dv5=BeU_KCMrVsHV2QuktOA+8AvuORrDzHFdpp8VDQNiQ at mail.gmail.com>
Content-Type: text/plain; charset="utf-8"

I am not expert in this but i can suggest few things try conv_thr=10^-8
and use ion/cell_dynamics=bfgs. Also which direction you want to move the
atoms?. I mean cell_dofree?. all the xyz direction?
Hope it helps you.
Manu


On Thu, Jan 5, 2017 at 12:35 PM, ???? ???????? <yuanqing.wang at riken.jp>
wrote:

> Dear QE users,
>
> I am trying to optimize the crystal structure of K2V8O21. The input file
> is given below. I tried many different sets (vc-realx and relax.
> constrained or not), or optimization algorithm (BFGS or damp).  However, I
> cannot get converged result. Can someone give me some suggestions? Thank
> you very much!
>
> Best,
>
> Yuanqing Wang
>
> postdoctor
> RIKEN, Japan
>
> ------One input file-------
> &control
>     calculation='vc-relax',
>     restart_mode = 'from_scratch',
>     prefix = 'k2v8o21',
>     outdir = './',
>     tprnfor = .TRUE.
>     pseudo_dir = '/pseudo/',
>     nstep=200
>  /
>  &system
>     ibrav = 0,
>     nat= 62, ntyp= 3,
>     ecutwfc = 150,
>     ecutrho = 600,
>     tot_charge=0,
>     occupations='smearing', smearing='mp', degauss=0.03
>  /
>  &electrons
>    mixing_beta = 0.3
>  /
>  &ions
>   ion_dynamics='damp'
>  /
>  &CELL
>   cell_dynamics='damp-pr'
>  /
> ATOMIC_SPECIES
>  K  39.0983 K.pz-hgh.UPF
>  V  50.942  V.pz-hgh.UPF
>  O  15.999  O.pz-hgh.UPF
> CELL_PARAMETERS angstrom
>  13.746484076   0.000000000  -0.193637952
>   0.000000000   3.360623858   0.000000000
>  -0.429832895   0.000000000  13.681512366
> ATOMIC_POSITIONS angstrom
> K       6.984312493   0.000000000   4.188728225 0 0 0
> K       6.332338675   0.000000000   9.299146598 0 0 0
> K       0.111143470   1.680311929   4.286848404 0 0 0
> K      13.205507698   1.680311929   9.201026418 0 0 0
> V      10.878749236   1.680311929  12.433287018
> V       2.437901942   1.680311929   1.054587499
> V       4.008352623   0.000000000  12.539262335
> V       9.308298554   0.000000000   0.948612182
> V      11.369939010   0.000000000   6.612591821
> V       1.946712158   0.000000000   6.875283001
> V       4.495045176   1.680311929   6.720753553
> V       8.821605991   1.680311929   6.767121270
> V      11.150388833   0.000000000   3.743423629
> V       2.166262335   0.000000000   9.744451194
> V       4.296183684   1.680311929   3.847414705
> V       9.020467484   1.680311929   9.640460118
> V      12.578611942   0.000000000   1.090039654
> V       0.738039229   0.000000000  12.397835067
> V       5.704373956   1.680311929   1.184004573
> V       7.612277214   1.680311929  12.303870148
> O      12.349856377   0.000000000   5.231345609
> O       0.966794818   0.000000000   8.256528398
> O       5.490033518   1.680311929   5.354972202
> O       7.826617675   1.680311929   8.132901806
> O      10.708076383   1.680311929   6.225623611
> O       2.608574796   1.680311929   7.262250803
> O       3.828996973   0.000000000   6.322373797
> O       9.487654207   0.000000000   7.165500618
> O      12.137386541   1.680311929   0.583012891
> O       1.179264646   1.680311929  12.904861320
> O       5.265470757  -0.000000000   0.685756586
> O       8.051180430   0.000000000  12.802117625
> O      11.927069357   1.680311929  11.327461557
> O       1.389581812   1.680311929   2.160413266
> O       5.060238394   0.000000000  11.437026216
> O       8.256412774   0.000000000   2.050848606
> O      10.802990364   0.000000000   1.920124897
> O       2.513660822   0.000000000  11.567749315
> O       3.937601468   1.680311929   2.030377822
> O       9.379049718   1.680311929  11.457496389
> O       9.720341944   0.000000000   4.289255974
> O       3.596309249   0.000000000   9.198618033
> O       2.865221165   1.680311929   4.391289428
> O      10.451430029   1.680311929   9.096584579
> O       1.048281817   0.000000000   5.602802054
> O      12.268369056   0.000000000   7.885072366
> O       7.933518947   1.680311929   5.487946834
> O       5.383132643   1.680311929   7.999927575
> O       2.692732203   0.000000000   0.478164303
> O      10.623918782   0.000000000  13.009709809
> O       9.564010497   1.680311929   0.367862997
> O       3.752640694   1.680311929  13.120011112
> O      -0.030603751   0.000000000  11.047477402
> O      13.347255188   0.000000000   2.440397009
> O       6.845321995   1.680311929  10.955939637
> O       6.471328777   1.680311929   2.531934783
> O       4.966539817   0.000000000   3.695467695
> O       8.350110955   0.000000000   9.792406726
> O      11.803635919   1.680311929   3.578686576
> O       1.513015671   1.680311929   9.909187834
> O       0.000000000   0.000000000   0.000000000
> O       6.873242038   1.680311929  -0.096818975
> K_POINTS automatic
> 1 2 1 1 1 1
>
> --------output of total force-------------
>     Total force =     0.051290     Total SCF correction =     0.002130
>      Total force =     0.051136     Total SCF correction =     0.002608
>      Total force =     0.050236     Total SCF correction =     0.002396
>      Total force =     0.049097     Total SCF correction =     0.001622
>      Total force =     0.047667     Total SCF correction =     0.001084
>      Total force =     0.046453     Total SCF correction =     0.001397
>      Total force =     0.044931     Total SCF correction =     0.000588
>      Total force =     0.043841     Total SCF correction =     0.001269
>      Total force =     0.042947     Total SCF correction =     0.001489
>      Total force =     0.042798     Total SCF correction =     0.001499
>      Total force =     0.043219     Total SCF correction =     0.001842
>      Total force =     0.043860     Total SCF correction =     0.002046
>      Total force =     0.045375     Total SCF correction =     0.001577
>      Total force =     0.046556     Total SCF correction =     0.001423
>      Total force =     0.047042     Total SCF correction =     0.001028
>      Total force =     0.047541     Total SCF correction =     0.001137
>      Total force =     0.046434     Total SCF correction =     0.000862
>      Total force =     0.046324     Total SCF correction =     0.001308
>      Total force =     0.046291     Total SCF correction =     0.001539
>      Total force =     0.046668     Total SCF correction =     0.001693
>      Total force =     0.047444     Total SCF correction =     0.002223
>      Total force =     0.047503     Total SCF correction =     0.001856
>      Total force =     0.047531     Total SCF correction =     0.000283
>      Total force =     0.047968     Total SCF correction =     0.000493
>      Total force =     0.048130     Total SCF correction =     0.000548
>      Total force =     0.048428     Total SCF correction =     0.000401
>      Total force =     0.049057     Total SCF correction =     0.001568
>      Total force =     0.049558     Total SCF correction =     0.001533
>      Total force =     0.050126     Total SCF correction =     0.000547
>      Total force =     0.051056     Total SCF correction =     0.002082
>      Total force =     0.051638     Total SCF correction =     0.001535
>      Total force =     0.052518     Total SCF correction =     0.001070
>      Total force =     0.053171     Total SCF correction =     0.000721
>      Total force =     0.053997     Total SCF correction =     0.002044
>      Total force =     0.055299     Total SCF correction =     0.000850
>      Total force =     0.057107     Total SCF correction =     0.001969
>      Total force =     0.058558     Total SCF correction =     0.001402
>      Total force =     0.060669     Total SCF correction =     0.001204
>      Total force =     0.063337     Total SCF correction =     0.001733
>      Total force =     0.065735     Total SCF correction =     0.001408
>      Total force =     0.068646     Total SCF correction =     0.002278
>      Total force =     0.071455     Total SCF correction =     0.001691
>      Total force =     0.074416     Total SCF correction =     0.001644
>      Total force =     0.077870     Total SCF correction =     0.001039
>      Total force =     0.082025     Total SCF correction =     0.001121
>      Total force =     0.086844     Total SCF correction =     0.000942
>      Total force =     0.092341     Total SCF correction =     0.001927
>      Total force =     0.098669     Total SCF correction =     0.002091
>      Total force =     0.114408     Total SCF correction =     0.001387
>      Total force =     0.114391     Total SCF correction =     0.000697
>      Total force =     0.124232     Total SCF correction =     0.002167
>      Total force =     0.136284     Total SCF correction =     0.002503
>      Total force =     0.150359     Total SCF correction =     0.001559
>      Total force =     0.166135     Total SCF correction =     0.001821
>      Total force =     0.184791     Total SCF correction =     0.001960
>
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