[QE-users] relax does not converge

Iurii TIMROV iurii.timrov at epfl.ch
Fri Nov 19 13:04:56 CET 2021


Dear Clarence,


> mixing_beta=0.7d0,


Try to decrease it to 0.1 or so


> vdw_corr = 'DFT-D3'


I would disable this, since you are not having a layered material


> input_dft='PBE',


Not need to specify this


> ecutwfc=75,

> ecutrho=500,


Forces and stresses converge slowly w.r.t. cutoffs, so you might consider to increase them


500/75 = 6.67. I would use a factor of 8 - 12 (known as "dual")


You might consider also changing pseudos (I recommend to check SSSP).


HTH


Iurii


--
Dr. Iurii TIMROV
Senior Research Scientist
Theory and Simulation of Materials (THEOS)
Swiss Federal Institute of Technology Lausanne (EPFL)
CH-1015 Lausanne, Switzerland
+41 21 69 34 881
http://people.epfl.ch/265334
________________________________
From: users <users-bounces at lists.quantum-espresso.org> on behalf of LEUNG Clarence <liangxy123 at hotmail.com>
Sent: Friday, November 19, 2021 8:31:13 AM
To: users at lists.quantum-espresso.org
Subject: [QE-users] relax does not converge

Dear QE users,

The vc-relax of unitcell of  LiFePO4 with 28 atoms is converged. Then, I build 2*2 supercell of  LiFePO4 with 112 atoms and do vc-relax with the same computational setting. It does not converge with very large estimated scf accuracy and  Total force (more than 10 thousands). I have attached my input file below, and it is very appreciated that you can give me some suggestion.


&CONTROL
  calculation='vc-relax',
  prefix='LFPO',
  etot_conv_thr = 3.5D-7 ,
  forc_conv_thr = 2.0D-4 ,
  nstep = 200 ,
  wf_collect = .true. ,
/
&SYSTEM
  ibrav=8,
  celldm(1)=17.7752225400d0, celldm(2)=1.1011434650d0, celldm(3)=1.2897413600d0,
  nat=112,
  ntyp=4,
  ecutwfc=75,
  ecutrho=500,
  input_dft='PBE',
  occupations='smearing',
  smearing = 'gaussian' ,
  degauss = 0.01 ,
  vdw_corr = 'DFT-D3' ,
  nspin = 2 ,
  starting_magnetization(1) = 0.5 ,
  lda_plus_u = .true. ,
  Hubbard_U(1) = 4.0 ,
/
&ELECTRONS
  conv_thr=1d-07,
  mixing_beta=0.7d0,
  mixing_mode ='local-TF',
  electron_maxstep = 1000 ,
  scf_must_converge = .false. ,
/
&IONS
/
&CELL
   cell_dofree ='ibrav'
/
ATOMIC_SPECIES
  Fe 55.845000d0 Fe.pbe-spn-kjpaw_psl.1.0.0.UPF
  O 15.999400d0 O.pbe-n-kjpaw_psl.1.0.0.UPF
  P 30.973800d0 P.pbe-n-kjpaw_psl.1.0.0.UPF
  Li 6.941 Li.pbe-s-kjpaw_psl.1.0.0.UPF
ATOMIC_POSITIONS {crystal}
  Li   0.0028020266d0   0.0008837106d0  -0.0007710574d0
  Li   0.0028020266d0   0.0008837106d0   0.4992289426d0
  Li   0.5028020266d0   0.0008837106d0  -0.0007710574d0
  Li   0.5028020266d0   0.0008837106d0   0.4992289426d0
  Li   0.2481620435d0   0.4989755011d0  -0.0009616159d0
  Li   0.2481620435d0   0.4989755011d0   0.4990383842d0
  Li   0.7481620435d0   0.4989755011d0  -0.0009616159d0
  Li   0.7481620435d0   0.4989755011d0   0.4990383842d0
  Li   0.2477722059d0   0.4985091240d0   0.2507564314d0
  Li   0.2477722059d0   0.4985091240d0   0.7507564315d0
  Li   0.7477722059d0   0.4985091240d0   0.2507564314d0
  Li   0.7477722059d0   0.4985091240d0   0.7507564315d0
  Li   0.0031195316d0   0.0004036088d0   0.2511788322d0
  Li   0.0031195316d0   0.0004036088d0   0.7511788323d0
  Li   0.5031195315d0   0.0004036088d0   0.2511788322d0
  Li   0.5031195315d0   0.0004036088d0   0.7511788323d0
  Fe   0.2360170476d0   0.2183813537d0   0.3752748894d0
  Fe   0.2360170476d0   0.2183813537d0   0.8752748894d0
  Fe   0.7360170476d0   0.2183813537d0   0.3752748894d0
  Fe   0.7360170476d0   0.2183813537d0   0.8752748894d0
  Fe   0.0147759848d0   0.7168261054d0   0.3750669797d0
  Fe   0.0147759848d0   0.7168261054d0   0.8750669797d0
  Fe   0.5147759847d0   0.7168261054d0   0.3750669797d0
  Fe   0.5147759847d0   0.7168261054d0   0.8750669797d0
  Fe   0.4833598124d0   0.2829059154d0   0.1248996861d0
  Fe   0.4833598124d0   0.2829059154d0   0.6248996861d0
  Fe   0.9833598124d0   0.2829059154d0   0.1248996861d0
  Fe   0.9833598124d0   0.2829059154d0   0.6248996861d0
  Fe   0.2645444168d0   0.7811747117d0   0.1251233794d0
  Fe   0.2645444168d0   0.7811747117d0   0.6251233793d0
  Fe   0.7645444167d0   0.7811747117d0   0.1251233794d0
  Fe   0.7645444167d0   0.7811747117d0   0.6251233793d0
   P   0.2086576631d0   0.0951986081d0   0.1251691065d0
   P   0.2086576631d0   0.0951986081d0   0.6251691066d0
   P   0.7086576631d0   0.0951986081d0   0.1251691065d0
   P   0.7086576631d0   0.0951986081d0   0.6251691066d0
   P   0.4549656906d0   0.4083076018d0   0.3746739334d0
   P   0.4549656906d0   0.4083076018d0   0.8746739334d0
   P   0.9549656907d0   0.4083076018d0   0.3746739334d0
   P   0.9549656907d0   0.4083076018d0   0.8746739334d0
   P   0.0413300737d0   0.5903695401d0   0.1249817297d0
   P   0.0413300737d0   0.5903695401d0   0.6249817297d0
   P   0.5413300737d0   0.5903695401d0   0.1249817297d0
   P   0.5413300737d0   0.5903695401d0   0.6249817297d0
   P   0.2946608052d0   0.9070147513d0   0.3750905985d0
   P   0.2946608052d0   0.9070147513d0   0.8750905985d0
   P   0.7946608052d0   0.9070147513d0   0.3750905985d0
   P   0.7946608052d0   0.9070147513d0   0.8750905985d0
   O   0.3727627487d0   0.0996553546d0   0.1246586783d0
   O   0.3727627487d0   0.0996553546d0   0.6246586783d0
   O   0.8727627488d0   0.0996553546d0   0.1246586783d0
   O   0.8727627488d0   0.0996553546d0   0.6246586783d0
   O   0.1183448058d0   0.4073032765d0   0.3748793998d0
   O   0.1183448058d0   0.4073032765d0   0.8748793998d0
   O   0.6183448058d0   0.4073032765d0   0.3748793998d0
   O   0.6183448058d0   0.4073032765d0   0.8748793998d0
   O   0.3780828312d0   0.5928547523d0   0.1248406873d0
   O   0.3780828312d0   0.5928547523d0   0.6248406873d0
   O   0.8780828311d0   0.5928547523d0   0.1248406873d0
   O   0.8780828311d0   0.5928547523d0   0.6248406873d0
   O   0.1311430216d0   0.9056948542d0   0.3751414458d0
   O   0.1311430216d0   0.9056948542d0   0.8751414458d0
   O   0.6311430217d0   0.9056948542d0   0.3751414458d0
   O   0.6311430217d0   0.9056948542d0   0.8751414458d0
   O   0.1036845204d0   0.4504961401d0   0.1249381265d0
   O   0.1036845204d0   0.4504961401d0   0.6249381265d0
   O   0.6036845203d0   0.4504961401d0   0.1249381265d0
   O   0.6036845203d0   0.4504961401d0   0.6249381265d0
   O   0.3593408169d0   0.0454651987d0   0.3749712718d0
   O   0.3593408169d0   0.0454651987d0   0.8749712718d0
   O   0.8593408168d0   0.0454651987d0   0.3749712718d0
   O   0.8593408168d0   0.0454651987d0   0.8749712718d0
   O   0.1467618741d0   0.9555692547d0   0.1257329289d0
   O   0.1467618741d0   0.9555692547d0   0.6257329289d0
   O   0.6467618741d0   0.9555692547d0   0.1257329289d0
   O   0.6467618741d0   0.9555692547d0   0.6257329289d0
   O   0.3903017808d0   0.5468656465d0   0.3746423031d0
   O   0.3903017808d0   0.5468656465d0   0.8746423031d0
   O   0.8903017808d0   0.5468656465d0   0.3746423031d0
   O   0.8903017808d0   0.5468656465d0   0.8746423031d0
   O   0.1400811288d0   0.1641493251d0   0.0226891710d0
   O   0.1400811288d0   0.1641493251d0   0.5226891710d0
   O   0.6400811289d0   0.1641493251d0   0.0226891710d0
   O   0.6400811289d0   0.1641493251d0   0.5226891710d0
   O   0.3874022990d0   0.3373444725d0   0.4768118347d0
   O   0.3874022990d0   0.3373444725d0   0.9768118347d0
   O   0.8874022990d0   0.3373444725d0   0.4768118347d0
   O   0.8874022990d0   0.3373444725d0   0.9768118347d0
   O   0.3873190362d0   0.3372361207d0   0.2725583277d0
   O   0.3873190362d0   0.3372361207d0   0.7725583277d0
   O   0.8873190362d0   0.3372361207d0   0.2725583277d0
   O   0.8873190362d0   0.3372361207d0   0.7725583277d0
   O   0.1414151973d0   0.1654139874d0   0.2275034267d0
   O   0.1414151973d0   0.1654139874d0   0.7275034266d0
   O   0.6414151973d0   0.1654139874d0   0.2275034267d0
   O   0.6414151973d0   0.1654139874d0   0.7275034266d0
   O   0.1098450997d0   0.6610655463d0   0.2269307379d0
   O   0.1098450997d0   0.6610655463d0   0.7269307378d0
   O   0.6098450997d0   0.6610655463d0   0.2269307379d0
   O   0.6098450997d0   0.6610655463d0   0.7269307378d0
   O   0.3615283987d0   0.8355435722d0   0.2727622665d0
   O   0.3615283987d0   0.8355435722d0   0.7727622665d0
   O   0.8615283987d0   0.8355435722d0   0.2727622665d0
   O   0.8615283987d0   0.8355435722d0   0.7727622665d0
   O   0.3615255798d0   0.8355756202d0   0.4773439176d0
   O   0.3615255798d0   0.8355756202d0   0.9773439176d0
   O   0.8615255798d0   0.8355756202d0   0.4773439176d0
   O   0.8615255798d0   0.8355756202d0   0.9773439176d0
   O   0.1100024943d0   0.6612139241d0   0.0231098062d0
   O   0.1100024943d0   0.6612139241d0   0.5231098063d0
   O   0.6100024943d0   0.6612139241d0   0.0231098062d0
   O   0.6100024943d0   0.6612139241d0   0.5231098063d0
K_POINTS {automatic}
  3 3 3 0 0 0


Thanks!
Best regards,
LIANG Xiongyi
Postdoctoral Fellow
The University of Hong Kong

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