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

[Dr. SUNIL KUMAR]

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
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20210202/01d379a5/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: 2.png
Type: image/png
Size: 76451 bytes
Desc: not available
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20210202/01d379a5/attachment.png>