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<p class="MsoNormal">Dear QE users,</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">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.</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">&CONTROL</p>
<p class="MsoNormal"> calculation='vc-relax',</p>
<p class="MsoNormal"> prefix='LFPO',</p>
<p class="MsoNormal"> etot_conv_thr = 3.5D-7 ,</p>
<p class="MsoNormal"> forc_conv_thr = 2.0D-4 ,</p>
<p class="MsoNormal"> nstep = 200 ,</p>
<p class="MsoNormal"> wf_collect = .true. ,</p>
<p class="MsoNormal">/</p>
<p class="MsoNormal">&SYSTEM</p>
<p class="MsoNormal"> ibrav=8,</p>
<p class="MsoNormal"> celldm(1)=17.7752225400d0, celldm(2)=1.1011434650d0, celldm(3)=1.2897413600d0,</p>
<p class="MsoNormal"> nat=112,</p>
<p class="MsoNormal"> ntyp=4,</p>
<p class="MsoNormal"> ecutwfc=75,</p>
<p class="MsoNormal"> ecutrho=500,</p>
<p class="MsoNormal"> input_dft='PBE',</p>
<p class="MsoNormal"> occupations='smearing',</p>
<p class="MsoNormal"> smearing = 'gaussian' ,</p>
<p class="MsoNormal"> degauss = 0.01 ,</p>
<p class="MsoNormal"> vdw_corr = 'DFT-D3' ,</p>
<p class="MsoNormal"> nspin = 2 ,</p>
<p class="MsoNormal"> starting_magnetization(1) = 0.5 ,</p>
<p class="MsoNormal"> lda_plus_u = .true. ,</p>
<p class="MsoNormal"> Hubbard_U(1) = 4.0 ,</p>
<p class="MsoNormal">/</p>
<p class="MsoNormal">&ELECTRONS</p>
<p class="MsoNormal"> conv_thr=1d-07,</p>
<p class="MsoNormal"> mixing_beta=0.7d0,</p>
<p class="MsoNormal"> mixing_mode ='local-TF',</p>
<p class="MsoNormal"> electron_maxstep = 1000 ,</p>
<p class="MsoNormal"> scf_must_converge = .false. ,</p>
<p class="MsoNormal">/</p>
<p class="MsoNormal">&IONS</p>
<p class="MsoNormal">/</p>
<p class="MsoNormal">&CELL</p>
<p class="MsoNormal"> cell_dofree ='ibrav' </p>
<p class="MsoNormal">/</p>
<p class="MsoNormal">ATOMIC_SPECIES</p>
<p class="MsoNormal"> Fe 55.845000d0 Fe.pbe-spn-kjpaw_psl.1.0.0.UPF</p>
<p class="MsoNormal"> O 15.999400d0 O.pbe-n-kjpaw_psl.1.0.0.UPF</p>
<p class="MsoNormal"> P 30.973800d0 P.pbe-n-kjpaw_psl.1.0.0.UPF</p>
<p class="MsoNormal"> Li 6.941 Li.pbe-s-kjpaw_psl.1.0.0.UPF</p>
<p class="MsoNormal">ATOMIC_POSITIONS {crystal}</p>
<p class="MsoNormal"> Li 0.0028020266d0 0.0008837106d0 -0.0007710574d0</p>
<p class="MsoNormal"> Li 0.0028020266d0 0.0008837106d0 0.4992289426d0</p>
<p class="MsoNormal"> Li 0.5028020266d0 0.0008837106d0 -0.0007710574d0</p>
<p class="MsoNormal"> Li 0.5028020266d0 0.0008837106d0 0.4992289426d0</p>
<p class="MsoNormal"> Li 0.2481620435d0 0.4989755011d0 -0.0009616159d0</p>
<p class="MsoNormal"> Li 0.2481620435d0 0.4989755011d0 0.4990383842d0</p>
<p class="MsoNormal"> Li 0.7481620435d0 0.4989755011d0 -0.0009616159d0</p>
<p class="MsoNormal"> Li 0.7481620435d0 0.4989755011d0 0.4990383842d0</p>
<p class="MsoNormal"> Li 0.2477722059d0 0.4985091240d0 0.2507564314d0</p>
<p class="MsoNormal"> Li 0.2477722059d0 0.4985091240d0 0.7507564315d0</p>
<p class="MsoNormal"> Li 0.7477722059d0 0.4985091240d0 0.2507564314d0</p>
<p class="MsoNormal"> Li 0.7477722059d0 0.4985091240d0 0.7507564315d0</p>
<p class="MsoNormal"> Li 0.0031195316d0 0.0004036088d0 0.2511788322d0</p>
<p class="MsoNormal"> Li 0.0031195316d0 0.0004036088d0 0.7511788323d0</p>
<p class="MsoNormal"> Li 0.5031195315d0 0.0004036088d0 0.2511788322d0</p>
<p class="MsoNormal"> Li 0.5031195315d0 0.0004036088d0 0.7511788323d0</p>
<p class="MsoNormal"> Fe 0.2360170476d0 0.2183813537d0 0.3752748894d0</p>
<p class="MsoNormal"> Fe 0.2360170476d0 0.2183813537d0 0.8752748894d0</p>
<p class="MsoNormal"> Fe 0.7360170476d0 0.2183813537d0 0.3752748894d0</p>
<p class="MsoNormal"> Fe 0.7360170476d0 0.2183813537d0 0.8752748894d0</p>
<p class="MsoNormal"> Fe 0.0147759848d0 0.7168261054d0 0.3750669797d0</p>
<p class="MsoNormal"> Fe 0.0147759848d0 0.7168261054d0 0.8750669797d0</p>
<p class="MsoNormal"> Fe 0.5147759847d0 0.7168261054d0 0.3750669797d0</p>
<p class="MsoNormal"> Fe 0.5147759847d0 0.7168261054d0 0.8750669797d0</p>
<p class="MsoNormal"> Fe 0.4833598124d0 0.2829059154d0 0.1248996861d0</p>
<p class="MsoNormal"> Fe 0.4833598124d0 0.2829059154d0 0.6248996861d0</p>
<p class="MsoNormal"> Fe 0.9833598124d0 0.2829059154d0 0.1248996861d0</p>
<p class="MsoNormal"> Fe 0.9833598124d0 0.2829059154d0 0.6248996861d0</p>
<p class="MsoNormal"> Fe 0.2645444168d0 0.7811747117d0 0.1251233794d0</p>
<p class="MsoNormal"> Fe 0.2645444168d0 0.7811747117d0 0.6251233793d0</p>
<p class="MsoNormal"> Fe 0.7645444167d0 0.7811747117d0 0.1251233794d0</p>
<p class="MsoNormal"> Fe 0.7645444167d0 0.7811747117d0 0.6251233793d0</p>
<p class="MsoNormal"> P 0.2086576631d0 0.0951986081d0 0.1251691065d0</p>
<p class="MsoNormal"> P 0.2086576631d0 0.0951986081d0 0.6251691066d0</p>
<p class="MsoNormal"> P 0.7086576631d0 0.0951986081d0 0.1251691065d0</p>
<p class="MsoNormal"> P 0.7086576631d0 0.0951986081d0 0.6251691066d0</p>
<p class="MsoNormal"> P 0.4549656906d0 0.4083076018d0 0.3746739334d0</p>
<p class="MsoNormal"> P 0.4549656906d0 0.4083076018d0 0.8746739334d0</p>
<p class="MsoNormal"> P 0.9549656907d0 0.4083076018d0 0.3746739334d0</p>
<p class="MsoNormal"> P 0.9549656907d0 0.4083076018d0 0.8746739334d0</p>
<p class="MsoNormal"> P 0.0413300737d0 0.5903695401d0 0.1249817297d0</p>
<p class="MsoNormal"> P 0.0413300737d0 0.5903695401d0 0.6249817297d0</p>
<p class="MsoNormal"> P 0.5413300737d0 0.5903695401d0 0.1249817297d0</p>
<p class="MsoNormal"> P 0.5413300737d0 0.5903695401d0 0.6249817297d0</p>
<p class="MsoNormal"> P 0.2946608052d0 0.9070147513d0 0.3750905985d0</p>
<p class="MsoNormal"> P 0.2946608052d0 0.9070147513d0 0.8750905985d0</p>
<p class="MsoNormal"> P 0.7946608052d0 0.9070147513d0 0.3750905985d0</p>
<p class="MsoNormal"> P 0.7946608052d0 0.9070147513d0 0.8750905985d0</p>
<p class="MsoNormal"> O 0.3727627487d0 0.0996553546d0 0.1246586783d0</p>
<p class="MsoNormal"> O 0.3727627487d0 0.0996553546d0 0.6246586783d0</p>
<p class="MsoNormal"> O 0.8727627488d0 0.0996553546d0 0.1246586783d0</p>
<p class="MsoNormal"> O 0.8727627488d0 0.0996553546d0 0.6246586783d0</p>
<p class="MsoNormal"> O 0.1183448058d0 0.4073032765d0 0.3748793998d0</p>
<p class="MsoNormal"> O 0.1183448058d0 0.4073032765d0 0.8748793998d0</p>
<p class="MsoNormal"> O 0.6183448058d0 0.4073032765d0 0.3748793998d0</p>
<p class="MsoNormal"> O 0.6183448058d0 0.4073032765d0 0.8748793998d0</p>
<p class="MsoNormal"> O 0.3780828312d0 0.5928547523d0 0.1248406873d0</p>
<p class="MsoNormal"> O 0.3780828312d0 0.5928547523d0 0.6248406873d0</p>
<p class="MsoNormal"> O 0.8780828311d0 0.5928547523d0 0.1248406873d0</p>
<p class="MsoNormal"> O 0.8780828311d0 0.5928547523d0 0.6248406873d0</p>
<p class="MsoNormal"> O 0.1311430216d0 0.9056948542d0 0.3751414458d0</p>
<p class="MsoNormal"> O 0.1311430216d0 0.9056948542d0 0.8751414458d0</p>
<p class="MsoNormal"> O 0.6311430217d0 0.9056948542d0 0.3751414458d0</p>
<p class="MsoNormal"> O 0.6311430217d0 0.9056948542d0 0.8751414458d0</p>
<p class="MsoNormal"> O 0.1036845204d0 0.4504961401d0 0.1249381265d0</p>
<p class="MsoNormal"> O 0.1036845204d0 0.4504961401d0 0.6249381265d0</p>
<p class="MsoNormal"> O 0.6036845203d0 0.4504961401d0 0.1249381265d0</p>
<p class="MsoNormal"> O 0.6036845203d0 0.4504961401d0 0.6249381265d0</p>
<p class="MsoNormal"> O 0.3593408169d0 0.0454651987d0 0.3749712718d0</p>
<p class="MsoNormal"> O 0.3593408169d0 0.0454651987d0 0.8749712718d0</p>
<p class="MsoNormal"> O 0.8593408168d0 0.0454651987d0 0.3749712718d0</p>
<p class="MsoNormal"> O 0.8593408168d0 0.0454651987d0 0.8749712718d0</p>
<p class="MsoNormal"> O 0.1467618741d0 0.9555692547d0 0.1257329289d0</p>
<p class="MsoNormal"> O 0.1467618741d0 0.9555692547d0 0.6257329289d0</p>
<p class="MsoNormal"> O 0.6467618741d0 0.9555692547d0 0.1257329289d0</p>
<p class="MsoNormal"> O 0.6467618741d0 0.9555692547d0 0.6257329289d0</p>
<p class="MsoNormal"> O 0.3903017808d0 0.5468656465d0 0.3746423031d0</p>
<p class="MsoNormal"> O 0.3903017808d0 0.5468656465d0 0.8746423031d0</p>
<p class="MsoNormal"> O 0.8903017808d0 0.5468656465d0 0.3746423031d0</p>
<p class="MsoNormal"> O 0.8903017808d0 0.5468656465d0 0.8746423031d0</p>
<p class="MsoNormal"> O 0.1400811288d0 0.1641493251d0 0.0226891710d0</p>
<p class="MsoNormal"> O 0.1400811288d0 0.1641493251d0 0.5226891710d0</p>
<p class="MsoNormal"> O 0.6400811289d0 0.1641493251d0 0.0226891710d0</p>
<p class="MsoNormal"> O 0.6400811289d0 0.1641493251d0 0.5226891710d0</p>
<p class="MsoNormal"> O 0.3874022990d0 0.3373444725d0 0.4768118347d0</p>
<p class="MsoNormal"> O 0.3874022990d0 0.3373444725d0 0.9768118347d0</p>
<p class="MsoNormal"> O 0.8874022990d0 0.3373444725d0 0.4768118347d0</p>
<p class="MsoNormal"> O 0.8874022990d0 0.3373444725d0 0.9768118347d0</p>
<p class="MsoNormal"> O 0.3873190362d0 0.3372361207d0 0.2725583277d0</p>
<p class="MsoNormal"> O 0.3873190362d0 0.3372361207d0 0.7725583277d0</p>
<p class="MsoNormal"> O 0.8873190362d0 0.3372361207d0 0.2725583277d0</p>
<p class="MsoNormal"> O 0.8873190362d0 0.3372361207d0 0.7725583277d0</p>
<p class="MsoNormal"> O 0.1414151973d0 0.1654139874d0 0.2275034267d0</p>
<p class="MsoNormal"> O 0.1414151973d0 0.1654139874d0 0.7275034266d0</p>
<p class="MsoNormal"> O 0.6414151973d0 0.1654139874d0 0.2275034267d0</p>
<p class="MsoNormal"> O 0.6414151973d0 0.1654139874d0 0.7275034266d0</p>
<p class="MsoNormal"> O 0.1098450997d0 0.6610655463d0 0.2269307379d0</p>
<p class="MsoNormal"> O 0.1098450997d0 0.6610655463d0 0.7269307378d0</p>
<p class="MsoNormal"> O 0.6098450997d0 0.6610655463d0 0.2269307379d0</p>
<p class="MsoNormal"> O 0.6098450997d0 0.6610655463d0 0.7269307378d0</p>
<p class="MsoNormal"> O 0.3615283987d0 0.8355435722d0 0.2727622665d0</p>
<p class="MsoNormal"> O 0.3615283987d0 0.8355435722d0 0.7727622665d0</p>
<p class="MsoNormal"> O 0.8615283987d0 0.8355435722d0 0.2727622665d0</p>
<p class="MsoNormal"> O 0.8615283987d0 0.8355435722d0 0.7727622665d0</p>
<p class="MsoNormal"> O 0.3615255798d0 0.8355756202d0 0.4773439176d0</p>
<p class="MsoNormal"> O 0.3615255798d0 0.8355756202d0 0.9773439176d0</p>
<p class="MsoNormal"> O 0.8615255798d0 0.8355756202d0 0.4773439176d0</p>
<p class="MsoNormal"> O 0.8615255798d0 0.8355756202d0 0.9773439176d0</p>
<p class="MsoNormal"> O 0.1100024943d0 0.6612139241d0 0.0231098062d0</p>
<p class="MsoNormal"> O 0.1100024943d0 0.6612139241d0 0.5231098063d0</p>
<p class="MsoNormal"> O 0.6100024943d0 0.6612139241d0 0.0231098062d0</p>
<p class="MsoNormal"> O 0.6100024943d0 0.6612139241d0 0.5231098063d0</p>
<p class="MsoNormal">K_POINTS {automatic}</p>
<p class="MsoNormal"> 3 3 3 0 0 0</p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:10.5pt;font-family:DengXian">Thanks<span lang="ZH-CN">!</span><o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:10.5pt;font-family:DengXian">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:10.5pt;font-family:DengXian">LIANG Xiongyi<o:p></o:p></span></p>
<p class="MsoNormal" style="text-align:justify;text-justify:inter-ideograph"><span style="font-size:10.5pt;font-family:DengXian">Postdoctoral Fellow<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:10.5pt;font-family:DengXian">The University of Hong Kong</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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