[Pw_forum] For optimization of a structure using relax calculation

Giuseppe Mattioli giuseppe.mattioli at ism.cnr.it
Sun Oct 22 13:25:44 CEST 2017


Dear Madhurya Chandel

There are several issues in your input that can induce instabilities  
in the scf iterations. But the first one dominates! Check always your  
structure. I did it with xcrysden and something is *badly* wrong, with  
Cu-O and Fe-O distances shorther than 1.2 A!!!

After you set up a correct structure there are further problems with  
your input

>                      ecutwfc = 30 ,
>                      ecutrho = 120,

>    Cu   63.54600  Cu.pbe-dn-rrkjus_psl.1.0.0.UPF
>    Fe   55.84500  Fe.pbe-spn-rrkjus_psl.1.0.0.UPF
>     O   15.99940  O.pbe-nl-rrkjus_psl.1.0.0.UPF

You are using ultrasoft pseudopotentials with a probably too low  
ecutwfc cutoff and with a badly unconverged ecutrho cutoff (ecutrho  
should be 8~12 times ecutwfc in the case of US pseudopotentials. If  
you are not familiar with such labels as ultrasoft, norm-conserving  
etc. please ask a supervisor or a skilled colleague, or flick through  
tutorials!). I would start with ecutwfc = 40 and ecutrho = 400, but  
you should check the convergence of your pseudopotentials on simpler  
systems.

>                  occupations = 'smearing' ,
>                      degauss = 0.005d0 ,
>                     smearing = 'methfessel-paxton' ,

Use gaussian smearing, it is more stable. You can switch to suitable  
schemes such as tetrahedra or mp or mv smearing after optimization of  
your system. 0.005 is a tight requirement for degauss that does not  
help convergence. Try with 0.01 or with a higher value. Look for the  
energy contribution of smearing in the output and you should have  
hints of the effect of smearing on your system to avoid spurious  
contributions.

>                     vdw_corr = 'grimme-d2'

not suitable for bulk metals or metal oxides

HTH
Giuseppe

Quoting Madhurya Chandel <madhurya.svnit at gmail.com>:

> Dear QE users
>
> I am doing relax calculation for copper ferrite. In the ouput file from
> starting its giving convergence has been achieved in 176 iterations. but at
> the end, it shows
> End of self-consistent calculation convergence NOT achieved after 500
> iterations: stopping. I didn't get any final enthalpy and coordinates but
> at the end, it is showing that Job is done.
> What does that mean ? Whether the relax calculation is completed or not?
> What can be the issue that at the end it has not converged?
> I am attaching the input please have a look.
>
>  &CONTROL
>                  calculation = 'relax' ,
>                 restart_mode = 'from_scratch' ,
>                   wf_collect = .true. ,
>                       outdir = '/home/madhuriya/Pure-CuF/' ,
>                       wfcdir = '/home/madhuriya/Pure-CuF/' ,
>                   pseudo_dir =
> '/opt/apps/quantum_espresso/qe-6.1/pseudo/pslibrary.1.0.0/pbe/PSEUDOPOTENTIALS/'
> ,
>                       prefix = 'pwscf' ,
>                    verbosity = 'low' ,
>                        nstep = 500 ,
>  /
>  &SYSTEM
>                        ibrav = 2,
>                    celldm(1) = 15.8169242979704d0,
>                          nat = 56,
>                         ntyp = 3,
>                      ecutwfc = 30 ,
>                      ecutrho = 120 ,
>                         nbnd = 600,
>                    input_dft = 'pbe' ,
>                  occupations = 'smearing' ,
>                      degauss = 0.005d0 ,
>                     smearing = 'methfessel-paxton' ,
>                        nspin = 2 ,
>    starting_magnetization(1) = 2.00000e-01,
>    starting_magnetization(2) = 2.00000e-01,
>    starting_magnetization(3) = 0.00000e+01,
>                     vdw_corr = 'grimme-d2' ,
>  /
>  &ELECTRONS
>             electron_maxstep = 500,
>                     conv_thr = 1d-06 ,
>                 adaptive_thr = .false. ,
>                  mixing_mode = 'local-TF' ,
>                  mixing_beta = 0.07d0 ,
>  /
>  &IONS
>                 ion_dynamics = 'bfgs' ,
>  /
> ATOMIC_SPECIES
>    Cu   63.54600  Cu.pbe-dn-rrkjus_psl.1.0.0.UPF
>    Fe   55.84500  Fe.pbe-spn-rrkjus_psl.1.0.0.UPF
>     O   15.99940  O.pbe-nl-rrkjus_psl.1.0.0.UPF
> ATOMIC_POSITIONS crystal
>    Fe      0.682447000    0.182447000    0.182447000
>    Fe      0.932447000    0.432447000    0.182447000
>    Fe      0.432447000    0.182447000    0.932447000
>    Fe      0.182447000    0.432447000    0.932447000
>    Fe      0.682447000    0.682447000    0.682447000
>    Fe      0.932447000    0.932447000    0.682447000
>    Fe      0.432447000    0.682447000    0.432447000
>    Fe      0.182447000    0.932447000    0.432447000
>    Fe      0.182447000    0.182447000    0.682447000
>    Fe      0.432447000    0.432447000    0.682447000
>    Fe      0.932447000    0.182447000    0.432447000
>    Fe      0.682447000    0.432447000    0.432447000
>    Fe      0.182447000    0.682447000    0.182447000
>    Fe      0.432447000    0.932447000    0.182447000
>    Fe      0.932447000    0.682447000    0.932447000
>    Fe      0.682447000    0.932447000    0.932447000
>    Cu      0.057447000    0.057447000    0.057447000
>    Cu      0.307447000    0.307447000    0.307447000
>    Cu      0.057447000    0.557447000    0.557447000
>    Cu      0.307447000    0.807447000    0.807447000
>    Cu      0.557447000    0.057447000    0.557447000
>    Cu      0.807447000    0.307447000    0.807447000
>    Cu      0.557447000    0.557447000    0.057447000
>    Cu      0.807447000    0.807447000    0.307447000
>     O      0.442553000    0.172341000    0.172341000
>     O      0.672341000    0.172341000    0.942553000
>     O      0.172341000    0.442553000    0.172341000
>     O      0.192553000    0.192553000    0.922341000
>     O      0.422341000    0.192553000    0.692553000
>     O      0.942553000    0.442553000    0.942553000
>     O      0.422341000    0.422341000    0.922341000
>     O      0.192553000    0.422341000    0.692553000
>     O      0.442553000    0.672341000    0.672341000
>     O      0.672341000    0.672341000    0.442553000
>     O      0.172341000    0.942553000    0.672341000
>     O      0.192553000    0.692553000    0.422341000
>     O      0.422341000    0.692553000    0.192553000
>     O      0.942553000    0.942553000    0.442553000
>     O      0.422341000    0.922341000    0.422341000
>     O      0.192553000    0.922341000    0.192553000
>     O      0.942553000    0.172341000    0.672341000
>     O      0.172341000    0.172341000    0.442553000
>     O      0.672341000    0.442553000    0.672341000
>     O      0.692553000    0.192553000    0.422341000
>     O      0.922341000    0.192553000    0.192553000
>     O      0.442553000    0.442553000    0.442553000
>     O      0.922341000    0.422341000    0.422341000
>     O      0.692553000    0.422341000    0.192553000
>     O      0.942553000    0.672341000    0.172341000
>     O      0.172341000    0.672341000    0.942553000
>     O      0.672341000    0.942553000    0.172341000
>     O      0.692553000    0.692553000    0.922341000
>     O      0.922341000    0.692553000    0.692553000
>     O      0.442553000    0.942553000    0.942553000
>     O      0.922341000    0.922341000    0.922341000
>     O      0.692553000    0.922341000    0.692553000
> K_POINTS automatic
>   8 8 8   0 0 0
>
> The end of the output file
> total cpu time spent up to now is  1254887.4 secs
>
>      total energy              =   -5830.47700122 Ry
>      Harris-Foulkes estimate   =   -5830.47771931 Ry
>      estimated scf accuracy    <       0.00822680 Ry
>
>      total magnetization       =    -0.00 Bohr mag/cell
>      absolute magnetization    =     0.09 Bohr mag/cell
>
>      End of self-consistent calculation
>
>      convergence NOT achieved after 500 iterations: stopping
>
>      Writing output data file pwscf.save
>
>      init_run     :    107.26s CPU    109.67s WALL (       1 calls)
>      electrons    : *********s CPU *********s WALL (       9 calls)
>      update_pot   :      1.36s CPU      1.47s WALL (       8 calls)
>      forces       :    436.43s CPU    441.48s WALL (       8 calls)
>
>      Called by init_run:
>      wfcinit      :    106.26s CPU    108.64s WALL (       1 calls)
>      potinit      :      0.10s CPU      0.10s WALL (       1 calls)
>
>      Called by electrons:
>      c_bands      : *********s CPU *********s WALL (    2263 calls)
>      sum_band     :  48289.63s CPU  49023.60s WALL (    2263 calls)
>      v_of_rho     :     76.92s CPU     76.05s WALL (    2272 calls)
>      newd         :     92.34s CPU     89.25s WALL (    2272 calls)
>      mix_rho      :     25.99s CPU     28.37s WALL (    2263 calls)
>
>      Called by c_bands:
>      init_us_2    :   1249.73s CPU   1426.91s WALL (  589550 calls)
>      cegterg      : *********s CPU *********s WALL (  294190 calls)
>
>      Called by sum_band:
>      sum_band:bec :    906.35s CPU   1188.81s WALL (  294190 calls)
>      addusdens    :    187.11s CPU    187.28s WALL (    2263 calls)
>
>      Called by *egterg:
>      h_psi        : 176860.03s CPU 179441.85s WALL (  709057 calls)
>      s_psi        :  37805.78s CPU  37083.48s WALL (  709057 calls)
>      g_psi        :    934.98s CPU   1160.22s WALL (  414737 calls)
>      cdiaghg      : 768709.94s CPU 768622.13s WALL (  707887 calls)
>
>      Called by h_psi:
>      h_psi:pot    : 174784.98s CPU 176653.96s WALL (  709057 calls)
>      h_psi:calbec :  37666.68s CPU  37092.65s WALL (  709057 calls)
>      vloc_psi     : 100273.20s CPU 102532.57s WALL (  709057 calls)
>      add_vuspsi   :  36841.45s CPU  37023.90s WALL (  709057 calls)
>
>      General routines
>      calbec       :  55921.29s CPU  55053.46s WALL ( 1007407 calls)
>      fft          :     11.13s CPU     16.68s WALL (   56918 calls)
>      ffts         :      6.60s CPU      7.31s WALL (   38495 calls)
>      fftw         : 106995.05s CPU 108896.79s WALL (******** calls)
>      davcio       :      0.02s CPU      0.53s WALL (     148 calls)
>
>      Parallel routines
>      fft_scatter  :  27359.92s CPU  28132.55s WALL (******** calls)
>
>      PWSCF        :    14d    6h54m CPU       14d   12h35m WALL
>
>
>    This run was terminated on:   6:25:17  21Oct2017
>
> =------------------------------------------------------------------------------=
>    JOB DONE.
> =------------------------------------------------------------------------------=
>
>
> Thank you in advance.
>
> With regards
>
> *Madhurya Chandel*
>
> *Research Scholar *
>
> *Department of Chemistry *
>
> *BITS PILANI, GOA campus*
>
> *+91-7507546773*



GIUSEPPE MATTIOLI
CNR - ISTITUTO DI STRUTTURA DELLA MATERIA
Via Salaria Km 29,300 - C.P. 10
I-00015 - Monterotondo Scalo (RM)
Mob (*preferred*) +39 373 7305625
Tel + 39 06 90672342 - Fax +39 06 90672316
E-mail: <giuseppe.mattioli at ism.cnr.it>




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