[QE-users] Relax calculation of strontium hexaferrite using QE

ABDELHAMID AIT M\'HID a.aitmhid at edu.umi.ac.ma
Thu Feb 4 15:55:42 CET 2021


Dear SUNIL,
convergence issues are often related to the  BAD CHOICE of ecutcfc and/Or
K_POINTS. I suggest you increase ecutwfc it seems too small and for ecutrho
let it be around ecutwfc* 8~12 since you use ultrasoft pseudopotential.
Also, increase K-POINTS try 4*4*3. another remarque is that since ibrav=4,
a and c seems to be bad description of cell parameters try to use celldm(1)
(in bohr) and celldm(3) instead (read pw.x input description)
I hope this solves the problem
best wishes.
Abdelhamid



Le mar. 2 févr. 2021 à 10:55, Dr. SUNIL KUMAR <suniliitd14 at gmail.com> a
écrit :

> Dear Developers and users of QE.
> I am struggling to optimize the structure of strontium hexaferrite durin
> relax calculation of DFT using QE as given in the following script and
> attached snapshot. It is taking too much time and send some unexpected
> error as
>
>      convergence NOT achieved after 100 iterations: stoppingv
> or
>      convergence NOT achieved after 200 iterations: stopping
>
> Can anyone suggest me any modification in the following script.
> I will be too much grateful.
> Thanks
> With regards
> SUNIL
>
> &CONTROL
>     calculation   = "relax"
>     prefix        = "espresso"
>     tprnfor       = .TRUE.
>     tstress       = .TRUE.
>     wf_collect    = .TRUE.
>     verbosity     = 'high'
>     disk_io       = 'high'
>     forc_conv_thr =  1.00000e-03
>     nstep         =  200
>     pseudo_dir    = "/home/pseudopot"
>     outdir        = "./outdir"
>     wfcdir        = "./wfcdir"
> /
>
> &SYSTEM
>     a                         =  5.99774e+00
>     c                         =  2.33482e+01
>     degauss                   =  1.00000e-02
>     ecutrho                   =  250
>     ecutwfc                   =  25
>     ibrav                     = 4
>     nat                       = 64
>     nspin                     = 2
>     ntyp                      = 3
>     occupations               = "smearing"
>     smearing                  = "gaussian"
>     starting_magnetization(1) =  0.00000e+00
>     starting_magnetization(2) =  0.2
>     starting_magnetization(3) =  0.00000e+00
>     lda_plus_u                = .true.
>     lda_plus_u_kind           = 0
>     Hubbard_U(2)              = 4
>     Hubbard_J(1,1)            = 0
>     Hubbard_J(2,2)            = 1
>
> /
>
> &ELECTRONS
>     conv_thr         =  1.00000e-06
>     electron_maxstep = 500
>     mixing_beta      =  4.00000e-01
>     startingpot      = "atomic"
>     startingwfc      = "atomic+random"
>
> /
>
> &IONS
>     ion_dynamics = "bfgs"
> /
>
> &CELL
> /
>
>
> K_POINTS {automatic}
>  3  3  1  0 0 0
>
> ATOMIC_SPECIES
> Sr     87.62000  Sr.pbe-nsp-van.UPF
> Fe     55.84500  Fe.pbe-nd-rrkjus.UPF
> O      15.99940  O.pbe-rrkjus.UPF
>
> ATOMIC_POSITIONS {angstrom}
> Sr     -0.000000   3.462796  17.511161
> Sr      2.998869   1.731398   5.837054
> Fe      0.000000   0.000000   0.000000
> Fe      0.000000   0.000000  11.674107
> Fe      0.000000   0.000000  17.511161
> Fe      0.000000   0.000000   5.837054
> Fe      2.998869   1.731398  22.706489
> Fe     -0.000000   3.462796   0.641726
> Fe     -0.000000   3.462796  11.032382
> Fe      2.998869   1.731398  12.315833
> Fe      2.998869   1.731398  18.887702
> Fe     -0.000000   3.462796   4.460513
> Fe     -0.000000   3.462796   7.213594
> Fe      2.998869   1.731398  16.134621
> Fe      2.998869   3.447345   2.560692
> Fe      1.512816   0.873424   2.560692
> Fe      4.484923   0.873424   2.560692
> Fe      0.000000   1.746849  20.787523
> Fe      1.486054   4.320769  20.787523
> Fe     -1.486054   4.320769  20.787523
> Fe      0.000000   1.746849  14.234800
> Fe      1.486054   4.320769  14.234800
> Fe     -1.486054   4.320769  14.234800
> Fe      2.998869   3.447345   9.113415
> Fe      1.512816   0.873424   9.113415
> Fe      4.484923   0.873424   9.113415
> O       0.000000   0.000000  19.782055
> O       0.000000   0.000000   3.566160
> O       0.000000   0.000000   8.107948
> O       0.000000   0.000000  15.240267
> O       2.998869   1.731398   1.300869
> O      -0.000000   3.462796  22.047346
> O      -0.000000   3.462796  12.974977
> O       2.998869   1.731398  10.373238
> O       2.998869   3.294521  17.511161
> O       1.645165   0.949836  17.511161
> O       4.352574   0.949836  17.511161
> O       0.000000   1.899672   5.837054
> O       1.353705   4.244357   5.837054
> O      -1.353705   4.244357   5.837054
> O       2.998869   3.580534  22.111857
> O       1.397470   0.806830  22.111857
> O       4.600268   0.806830  22.111857
> O       0.000000   1.613659   1.236358
> O       1.601399   4.387364   1.236358
> O      -1.601399   4.387364   1.236358
> O       0.000000   1.613659  10.437749
> O       1.601399   4.387364  10.437749
> O      -1.601399   4.387364  10.437749
> O       2.998869   3.580534  12.910466
> O       1.397470   0.806830  12.910466
> O       4.600268   0.806830  12.910466
> O       0.000000   5.134086  19.813669
> O      -1.447380   2.627150  19.813669
> O       1.447380   2.627150  19.813669
> O       2.998869   0.060107   3.534546
> O       4.446249   2.567043   3.534546
> O       1.551489   2.567043   3.534546
> O       2.998869   0.060107   8.139561
> O       4.446249   2.567043   8.139561
> O       1.551489   2.567043   8.139561
> O       0.000000   5.134086  15.208654
> O      -1.447380   2.627150  15.208654
> O       1.447380   2.627150  15.208654
>
>
> Dr. Sunil Kumar
> Ph.D (Chemical Engg. IIT Delhi)
> M.Tech (Chemical Engg. IIT Delhi)
> B.Tech (Chemical Engg. IET-CSJMU Kanpur)
> Scientist-C and Assistant Professor
> CSIR-National Metallurgical Laboratory Jamshedpur-831007
> http://www.nmlindia.org/
> https://scholar.google.co.in/citations?user=OchYqugAAAAJ&hl=en&oi=sra
>
> _______________________________________________
> Quantum ESPRESSO is supported by MaX (www.max-centre.eu)
> users mailing list users at lists.quantum-espresso.org
> https://lists.quantum-espresso.org/mailman/listinfo/users
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20210204/f53e7f73/attachment.html>


More information about the users mailing list