Dear Giuseppe, Thanks very much for your suggestion.
________________________________ 发件人: users <[email protected]> 代表 Giuseppe Mattioli <[email protected]> 发送时间: 2019年3月21日 18:00 收件人: [email protected] 主题: Re: [QE-users] scf not converge in neb.x caluculation Dear Liang Xiongyi There are a lot of things you can try, but neb.x can be somewhat whimsical... 1) You can change the total number of images. This will change the starting points and might ensure a smoother convergence. 2) path_thr = 0.05D0 This does not help convergence, but it is a bit tight in my experience. 0.1 is generally tight enough (in reasonably complex systems) to provide meaningful results. 3) degauss = 0.005 This is very tight and can hinder convergence. You should try to use 0.01~0.02 (check how much it affects total energies of images by looking at the -TS contribution in the PW.out files) 4) mixing_beta=0.7d0 You can lower this even down to 0.01 (but 0.1 is generally a good value for not extremely stubborn convergence). 5) you are using a default electron_maxstep=100 value. You can raise this value, or you can raise (a littele bit) conv_thr. You may also carefully use scf_must_converge=.false., specially if scf cycles dance close to convergence and you want to force the system to step across a problematic atomic configuration. 6) K_POINTS {automatic} 5 5 1 0 0 0 This might be too much for calculation of barriers in a quite large supercell having no symmetry. For example, I would check if the total energy difference between the converged final and initial images was (almost) constant by using K_POINTS {gamma}. If this was true, then I would calculate the whole path by using gamma_only tricks, which should also provide better convergence for the system. HTH Giuseppe LEUNG Clarence <[email protected]> ha scritto: > Dear QE users, > > I want to calculate the mobility of metal atom on surface bu neb.x. > However, the image 9 is very difficult to converge. Could you please > give me some advice. The input file as follows: > > Thanks. > LIANG XIongyi > City University of Hong Kong > > BEGIN > BEGIN_PATH_INPUT > &PATH > restart_mode = 'from_scratch' > string_method = 'neb', > nstep_path = 30, > ds = 1.D0, > opt_scheme = "broyden", > num_of_images = 10, > k_max = 0.3D0, > k_min = 0.2D0, > path_thr = 0.05D0, > > / > END_PATH_INPUT > > BEGIN_ENGINE_INPUT > &CONTROL > prefix='av-y', > outdir='/home/qeuser/Clarence/phosphorene/v/d3/av/neb', > pseudo_dir='/home/qeuser/SSSP_acc_PBE' , > verbosity='low', > etot_conv_thr = 1.0D-5 , > forc_conv_thr = 6.0D-4 , > nstep = 200 , > wf_collect = .true. , > verbosity='low', > / > &SYSTEM > ibrav=8, > celldm(1)=25.0298004651d0, celldm(2)=1.3810663486d0, > celldm(3)=1.8874762178d0, > nat=65, > ntyp=2, > ecutwfc=50, > ecutrho=500, > input_dft='PBE', > occupations='smearing', > smearing = 'gaussian' , > degauss = 0.005 , > nspin = 2 , > starting_magnetization(1) = 0.5 , > vdw_corr = 'DFT-D3' , > / > > &ELECTRONS > conv_thr=1d-06, > mixing_beta=0.7d0, > mixing_mode ='local-TF', > electron_maxstep = 1000 , > / > &IONS > / > > ATOMIC_SPECIES > P 30.973800d0 P.pbe-n-rrkjus_psl.1.0.0.UPF > V 50.941500d0 V_pbe_v1.uspp.F.UPF > > K_POINTS {automatic} > 5 5 1 0 0 0 > > BEGIN_POSITIONS > FIRST_IMAGE > ATOMIC_POSITIONS {crystal} > P 0.062364056 0.146835680 0.461004179 > P 0.187979850 0.227571721 0.458486567 > P 0.187359072 0.023967396 0.547448145 > P 0.062390271 0.105486489 0.546314111 > P 0.062391562 0.397230966 0.452233415 > P 0.187453676 0.479039381 0.452606421 > P 0.189364962 0.278117380 0.541172586 > P 0.062407749 0.357692419 0.537875656 > P 0.062401956 0.644403307 0.461059945 > P 0.188082333 0.725080248 0.462700469 > P 0.188395810 0.514757114 0.539192335 > P 0.062460702 0.595965919 0.543895751 > P 0.062381001 0.895525242 0.463867650 > P 0.186790459 0.977279845 0.463560403 > P 0.187798718 0.768448197 0.547468271 > P 0.062423049 0.849704828 0.548098847 > P 0.312659868 0.146168383 0.460453461 > P 0.437781276 0.227744221 0.458426404 > P 0.437455901 0.023776880 0.547310817 > P 0.312549613 0.105320407 0.545904997 > P 0.312139598 0.397030501 0.450854221 > P 0.438074098 0.477737365 0.445066729 > P 0.439912044 0.279485733 0.540862256 > P 0.314542445 0.359645859 0.537231792 > P 0.314544837 0.644905805 0.460878636 > P 0.434594009 0.730077067 0.459781958 > P 0.448827043 0.514927416 0.532500900 > P 0.317525398 0.592780735 0.543968174 > P 0.311728367 0.896097058 0.463720553 > P 0.436893865 0.977260819 0.463347579 > P 0.437860024 0.769032959 0.545891816 > P 0.312518709 0.850247622 0.547849195 > P 0.562393332 0.146370379 0.460376779 > P 0.686969347 0.227774704 0.458451805 > P 0.687291897 0.023755188 0.547362489 > P 0.562382204 0.105350763 0.545849427 > P 0.562473269 0.396448431 0.443507308 > P 0.686748477 0.477847993 0.445052781 > P 0.684946773 0.279498604 0.540893439 > P 0.562452036 0.365431435 0.533574680 > P 0.562388294 0.651473527 0.453514755 > P 0.690184909 0.730079028 0.459780328 > P 0.676015132 0.514980165 0.532495771 > P 0.562386005 0.604919173 0.537701074 > P 0.562374845 0.896356486 0.463525401 > P 0.687848329 0.977264329 0.463389247 > P 0.686894465 0.769048044 0.545881597 > P 0.562366018 0.850830890 0.547709669 > P 0.812039406 0.146172639 0.460500457 > P 0.936731753 0.227556339 0.458506445 > P 0.937413894 0.023975028 0.547450256 > P 0.812195810 0.105311249 0.545951465 > P 0.812689390 0.397151038 0.450847120 > P 0.937418545 0.479112680 0.452648391 > P 0.935397084 0.278168840 0.541173905 > P 0.810251826 0.359711909 0.537223718 > P 0.810287195 0.644943491 0.460914925 > P 0.936753166 0.725104783 0.462754832 > P 0.936455552 0.514807673 0.539237217 > P 0.807300389 0.592829495 0.544001475 > P 0.813022989 0.896104987 0.463696223 > P 0.937973444 0.977284048 0.463557949 > P 0.937000660 0.768483060 0.547514207 > P 0.812240625 0.850260753 0.547823269 > V 0.562457425 0.460038104 0.589861636 > LAST_IMAGE > ATOMIC_POSITIONS {crystal} > P 0.062445615 0.146456673 0.451477017 > P 0.187505780 0.228300342 0.450996126 > P 0.189411819 0.029049537 0.541552681 > P 0.062449177 0.108536309 0.537537957 > P 0.062447760 0.395196377 0.458733376 > P 0.188131570 0.475920562 0.460828460 > P 0.188374349 0.265401889 0.537271427 > P 0.062442541 0.346561452 0.541532408 > P 0.062445852 0.646720019 0.463330906 > P 0.186881361 0.728456886 0.463846544 > P 0.187786345 0.518231310 0.545890007 > P 0.062453053 0.599463807 0.547113520 > P 0.062449884 0.896772437 0.462088203 > P 0.188068030 0.977403357 0.459227449 > P 0.187407760 0.773919686 0.548121428 > P 0.062451045 0.855509144 0.547403030 > P 0.312157931 0.146197729 0.450100263 > P 0.437962144 0.226895792 0.443334809 > P 0.439781032 0.030364618 0.541401226 > P 0.314537903 0.110579019 0.536930990 > P 0.314516246 0.395673292 0.458770827 > P 0.434514870 0.480945643 0.457958047 > P 0.448849945 0.265612968 0.530384087 > P 0.317545829 0.343415876 0.541814557 > P 0.311882120 0.647337595 0.463336957 > P 0.437025970 0.728486497 0.463886605 > P 0.437893522 0.518734801 0.544383856 > P 0.312565523 0.599936087 0.546984686 > P 0.312792214 0.896123190 0.461534507 > P 0.437703418 0.977802230 0.459342638 > P 0.437537090 0.773854879 0.548208275 > P 0.312529860 0.855396994 0.547005515 > P 0.562445549 0.145582412 0.442645546 > P 0.686938850 0.226884972 0.443352934 > P 0.685108766 0.030376879 0.541401741 > P 0.562439931 0.116211878 0.533161816 > P 0.562454842 0.402446010 0.451051275 > P 0.690383198 0.480958602 0.457954855 > P 0.676029527 0.265601905 0.530394460 > P 0.562442494 0.355543724 0.535081296 > P 0.562448326 0.647583315 0.463280787 > P 0.687873726 0.728484011 0.463890075 > P 0.687007439 0.518737405 0.544382783 > P 0.562448794 0.600455024 0.546972980 > P 0.562448881 0.896623478 0.461579252 > P 0.687191466 0.977803753 0.459347311 > P 0.687350603 0.773851566 0.548211631 > P 0.562445632 0.855549232 0.547048125 > P 0.812742443 0.146187679 0.450102692 > P 0.937382360 0.228298381 0.450991288 > P 0.935497478 0.029039399 0.541554721 > P 0.810375354 0.110570352 0.536929886 > P 0.810378355 0.395682293 0.458771630 > P 0.936769992 0.475925052 0.460830172 > P 0.936505251 0.265408800 0.537265660 > P 0.807335019 0.343422437 0.541813266 > P 0.813017687 0.647336128 0.463349568 > P 0.938011871 0.728458147 0.463853218 > P 0.937122704 0.518229776 0.545892176 > P 0.812342101 0.599934329 0.546995984 > P 0.812096929 0.896122158 0.461548112 > P 0.936825737 0.977397364 0.459230552 > P 0.937491966 0.773921441 0.548127880 > P 0.812360758 0.855393535 0.547018412 > V 0.562433776 0.211933054 0.588349784 > END_POSITIONS > END_ENGINE_INPUT > END 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: <[email protected]> _______________________________________________ users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
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