<div dir="ltr"><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Hi,</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I do not know much about your system, i could see you are using inputdft='PBE', i do not think it is required. If you read the manual carefully it is written that 'use with carefully, if you know what you are doing'.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">I could see you are using different PP for Oxygen try to use same PPs. That might help, i am not sure.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">May be you could get better feedback from experts.</div><div class="gmail_default" style="font-family:arial,helvetica,sans-serif">Manu</div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Mon, Jun 17, 2019 at 9:46 AM Vidushi Sharma <<a href="mailto:vidushi.sharma@stonybrook.edu">vidushi.sharma@stonybrook.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">
<div>
<div dir="ltr">
<div>Hi,</div>
<div><br>
</div>
<div>I am new to using Quantum Espresso and I have a question about the convergence of a single point calculation ('scf') for a big system. The system is not complicated at all -- just has one NaCl with 96 H_{2}O molecules, but the box size itself has to be
of the order of 15 Ang, and this is not easy to converge. I have included my input file and the names of the pseudopotentials I use from the set provided on the QE page -- any suggestions to help the system converge are welcome! So far I have already looked
at ample of questions posted by people facing convergence issues but nothing has improved the situation, and I have tested convergence on
<b>smaller sized</b> boxes and that seems to work fine with the given pseudopotentials and other input parameters.</div>
<div><br>
</div>
<div><<a href="http://nacl96h2o.in" target="_blank">nacl96h2o.in</a>></div>
<div> &control<br>
calculation = 'scf',<br>
prefix = 'nacl_bh20',<br>
outdir = './tmp/'<br>
pseudo_dir = './pseudo/'<br>
/<br>
&system<br>
ibrav = 0, <br>
celldm(1) = 2.7161, <br>
nat = 290, <br>
ntyp = 4,<br>
ecutwfc = 30,<br>
ecutrho = 300,<br>
input_dft = 'pbe'<br>
/<br>
&electrons<br>
electron_maxstep = 500<br>
mixing_beta = 0.1<br>
/<br>
CELL_PARAMETERS cubic<br>
10.0 0.0 0.0<br>
0.0 10.0 0.0<br>
0.0 0.0 10.0<br>
<br>
ATOMIC_SPECIES<br>
H 1.008 H.pbe-kjpaw_psl.1.0.0.UPF <br>
O 15.999 O.pbe-n-rrkjus_psl.1.0.0.UPF <br>
Na 22.990 Na.pbe-spn-kjpaw_psl.1.0.0.UPF<br>
Cl 35.453 Cl.pbe-n-kjpaw_psl.1.0.0.UPF <br>
<br>
ATOMIC_POSITIONS (angstrom)<br>
Na 4.867210 6.569511 3.191487<br>
Cl 3.022620 6.024626 3.739746<br>
H 4.927055 10.441872 10.973286<br>
O 5.265258 11.309878 11.237590<br>
O 4.017527 10.622927 10.687648<br>
H 10.513380 12.871681 6.303561<br>
O 10.299966 13.812005 6.240642<br>
O 9.894495 12.512459 6.936896<br>
H 9.703393 1.257187 5.788580<br>
O 9.038896 1.890310 6.079435<br>
O 10.285630 1.775452 5.225542<br>
H 13.566921 11.356925 11.825488<br>
O 12.924065 12.026841 11.564094<br>
O 13.781250 10.904109 10.994968<br>
H 10.242246 12.399511 3.642226<br>
O 10.066306 12.118387 4.538761<br>
O 9.555536 13.037468 3.451166<br>
H 5.829184 8.701401 2.767993<br>
O 6.729539 9.014773 2.761105<br>
O 5.386785 9.232181 2.090447<br>
H 11.091427 3.643833 10.607679<br>
O 11.811736 4.275171 10.644902<br>
O 11.335723 2.981156 11.264805<br>
H 9.454174 9.724098 11.479173<br>
O 8.691027 10.116981 11.907536<br>
O 10.214669 10.182383 11.840996<br>
H 4.987285 14.324963 2.598627<br>
O 4.164732 0.116950 3.044210<br>
O 4.734860 13.960167 1.751422<br>
H 11.168902 1.973517 13.167202<br>
O 11.713195 2.466000 13.815669<br>
O 11.141319 1.075927 13.519426<br>
H 5.117969 2.634384 2.298544<br>
O 5.233954 1.711059 2.548705<br>
O 6.006517 2.987438 2.263779<br>
H 2.310572 7.428690 11.436984<br>
O 1.479980 6.953150 11.520516<br>
O 2.994438 6.771515 11.589829<br>
H 10.442356 9.367202 4.517214<br>
O 10.435523 9.843960 3.688311<br>
O 9.516179 9.363463 4.811819<br>
H 7.385970 1.426864 11.920237<br>
O 7.933397 1.724601 12.655179<br>
O 8.025128 1.093024 11.291179<br>
H 1.020593 2.001328 10.016276<br>
O 1.185432 2.127692 10.941944<br>
O 1.686152 1.378979 9.732610<br>
H 13.782330 3.290728 5.058812<br>
O 13.840035 2.871929 5.932143<br>
O 14.368339 2.769240 4.517663<br>
H 10.505698 10.102401 1.756034<br>
O 11.122516 10.281291 1.048208<br>
O 10.165230 10.961529 1.992476<br>
H 8.300607 5.454676 13.829578<br>
O 9.130585 5.611865 14.271766<br>
O 8.529094 5.384478 12.896466<br>
H 8.127639 5.739223 8.596007<br>
O 7.865767 6.662846 8.631549<br>
O 8.449893 5.573423 9.491189<br>
H 3.199780 10.559924 4.401587<br>
O 2.586694 10.215005 3.735467<br>
O 3.249385 9.885630 5.080991<br>
H 5.713466 11.322698 4.713134<br>
O 4.914592 11.026943 4.320960<br>
O 5.830766 12.191497 4.342987<br>
H 0.385969 12.163029 1.301139<br>
O 0.346916 13.114277 1.243542<br>
O 14.188198 11.950198 2.049644<br>
H 13.011027 2.643821 0.842728<br>
O 12.754584 2.331435 1.708804<br>
O 13.640876 1.988495 0.519065<br>
H 6.931294 9.346607 13.782798<br>
O 6.354101 8.621786 13.489437<br>
O 7.440681 8.973331 0.124115<br>
H 12.433086 8.971692 6.683760<br>
O 12.150275 8.306837 7.313441<br>
O 11.645473 9.141284 6.152326<br>
H 13.055595 12.091450 7.048727<br>
O 13.466587 12.922496 7.308617<br>
O 12.197462 12.343484 6.653975<br>
H 0.116658 4.687688 1.679807<br>
O 13.818174 4.056432 1.403838<br>
O 0.389399 4.404455 2.551999<br>
H 2.810947 10.512739 1.219633<br>
O 2.029966 11.078473 1.299794<br>
O 2.625997 9.935129 0.494591<br>
H 13.692304 1.772216 7.294778<br>
O 12.740134 1.931271 7.375310<br>
O 14.093933 2.452758 7.849110<br>
H 3.756586 1.852312 6.287004<br>
O 4.661857 1.858215 5.988074<br>
O 3.296722 1.396284 5.591416<br>
H 5.013538 3.351031 11.806268<br>
O 5.667354 2.646508 11.788579<br>
O 4.536437 3.271915 10.985177<br>
H 6.120018 4.506023 7.273240<br>
O 5.428645 4.458205 7.944853<br>
O 6.908423 4.868345 7.731643<br>
H 10.564147 5.914150 0.851846<br>
O 11.297190 6.391602 0.500389<br>
O 10.761905 5.757775 1.769700<br>
H 4.209058 12.791475 0.280627<br>
O 3.605348 12.787683 13.898476<br>
O 3.983161 11.999365 0.761822<br>
H 6.781484 12.022692 13.963930<br>
O 6.727285 11.066180 13.867317<br>
O 5.869490 12.310230 14.071349<br>
H 6.310932 13.150393 11.440921<br>
O 6.431318 14.095211 11.464492<br>
O 6.400192 12.859149 12.360045<br>
H 1.980944 12.252419 6.107114<br>
O 2.202650 11.602418 5.442023<br>
O 1.077861 12.048021 6.346127<br>
H 4.690337 6.089800 11.822453<br>
O 5.360804 6.388037 11.213363<br>
O 4.891455 5.153594 11.979456<br>
H 11.083520 6.389237 3.367335<br>
O 11.996878 6.127900 3.534797<br>
O 11.003236 7.259621 3.742246<br>
H 13.274863 11.046655 3.193857<br>
O 12.579058 11.676604 3.333482<br>
O 13.260408 10.466810 3.952280<br>
H 8.872945 5.047963 11.111122<br>
O 9.230930 5.937410 10.954740<br>
O 9.542287 4.442152 10.794840<br>
H 0.451212 7.710015 1.416153<br>
O 0.683966 6.830906 1.655804<br>
O 1.143971 7.978834 0.816618<br>
H 8.444275 2.671614 14.296021<br>
O 9.288997 2.441563 13.910468<br>
O 8.280653 3.569879 14.014529<br>
H 6.459516 6.860116 5.230569<br>
O 6.123324 6.315491 5.953433<br>
O 7.292196 6.445562 4.990060<br>
H 14.253197 0.322980 0.589961<br>
O 0.395995 0.482805 14.172782<br>
O 13.396323 0.015569 0.261483<br>
H 7.925063 14.078269 3.552169<br>
O 7.269108 0.308592 3.153432<br>
O 8.154069 0.131098 4.376061<br>
H 8.959624 13.215240 10.765021<br>
O 8.047759 13.057036 10.980113<br>
O 9.021536 13.063602 9.819968<br>
H 3.066014 0.653318 9.085639<br>
O 3.506412 1.320280 8.541030<br>
O 3.448989 14.215855 8.803568<br>
H 8.445248 8.287719 1.334805<br>
O 9.105063 7.753954 0.856524<br>
O 8.917019 9.097561 1.566098<br>
H 11.429143 2.335868 3.858027<br>
O 11.675925 1.442362 3.574269<br>
O 12.204733 2.644049 4.338440<br>
H 13.354510 5.966928 9.874683<br>
O 13.789329 5.820085 10.731269<br>
O 13.884401 5.448158 9.250328<br>
H 13.748491 10.353042 9.211821<br>
O 13.324978 10.857040 8.523345<br>
O 14.101161 9.588461 8.766131<br>
H 3.569789 1.883910 13.653641<br>
O 4.064447 2.282077 12.941204<br>
O 4.090613 2.054684 0.049521<br>
H 11.140485 1.957873 8.592517<br>
O 10.443164 2.320496 8.038523<br>
O 11.142660 2.524443 9.369447<br>
H 2.465981 11.089071 9.939744<br>
O 1.618936 10.936876 9.509961<br>
O 2.898414 11.751751 9.376324<br>
H 2.335577 8.432626 14.074842<br>
O 3.095595 7.882333 14.228272<br>
O 2.286556 8.545374 13.118974<br>
H 1.276355 0.663073 12.705923<br>
O 2.068326 1.134119 12.953695<br>
O 1.600297 14.199693 12.366240<br>
H 11.438586 13.195259 11.730789<br>
O 11.939166 13.662581 11.047674<br>
O 10.536523 13.153140 11.379754<br>
H 7.543757 9.464864 4.924522<br>
O 6.948121 10.200637 4.798178<br>
O 6.985251 8.693839 5.014859<br>
H 0.089816 5.866065 12.280984<br>
O 13.963163 6.340195 12.949559<br>
O 0.470776 5.096317 12.734193<br>
H 0.784890 1.259950 3.393559<br>
O 0.350970 0.924577 2.612637<br>
O 1.351487 1.961401 3.062714<br>
H 1.355084 3.814694 13.615672<br>
O 2.227064 3.454467 13.747785<br>
O 1.063317 4.074885 0.124062<br>
H 3.626148 12.687697 8.037170<br>
O 3.026220 12.319487 7.379165<br>
O 4.487389 12.347781 7.775430<br>
H 7.873957 2.652922 2.595999<br>
O 8.034399 3.541204 2.934007<br>
O 8.363971 2.618829 1.765769<br>
H 6.230319 7.883032 10.181265<br>
O 5.735556 8.612376 10.530609<br>
O 6.683240 8.241272 9.425185<br>
H 2.407346 4.210697 7.030739<br>
O 2.848246 3.491015 6.558082<br>
O 2.295683 4.904306 6.367323<br>
H 3.671794 8.139713 6.036689<br>
O 4.271273 7.697943 6.659497<br>
O 3.584450 7.521915 5.321453<br>
H 8.829549 13.412907 0.585991<br>
O 8.592220 14.102131 1.206679<br>
O 7.998748 12.980611 0.383450<br>
H 2.443830 12.538891 12.560835<br>
O 1.575220 12.173028 12.648057<br>
O 2.678483 12.409693 11.646485<br>
H 0.534107 13.873962 8.287769<br>
O 0.022520 0.274723 8.024468<br>
O 1.442664 14.139814 8.191882<br>
H 0.364690 9.744231 6.043366<br>
O 13.797970 9.587365 6.128301<br>
O 0.547946 9.542747 5.124702<br>
H 9.565251 3.827275 7.247780<br>
O 10.415887 4.268975 7.389913<br>
O 8.938873 4.384416 7.698194<br>
H 13.540610 6.144147 4.940110<br>
O 13.786015 5.241364 5.152882<br>
O 14.177865 6.664019 5.439124<br>
H 6.483650 6.233767 1.404497<br>
O 7.051697 6.982300 1.600908<br>
O 7.059132 5.596429 0.995926<br>
H 3.592029 7.510042 9.040455<br>
O 4.389035 7.569923 9.560856<br>
O 2.901807 7.889327 9.590652<br>
H 1.140225 7.185179 6.958092<br>
O 0.898785 8.105436 6.823741<br>
O 2.076957 7.150791 6.801894<br>
H 12.776424 7.353301 13.990676<br>
O 12.813274 8.268671 13.760081<br>
O 13.385771 7.254497 0.355907<br>
H 12.185343 14.216578 2.763006<br>
O 11.973102 14.101034 1.836881<br>
O 11.530400 13.718416 3.242987<br>
H 12.590676 0.081501 9.871654<br>
O 12.183736 0.685923 9.248364<br>
O 13.514462 0.340792 9.885274<br>
H 10.529125 7.165842 10.860387<br>
O 10.780397 7.181242 9.935563<br>
O 10.292923 8.067736 11.059361<br>
H 9.542964 9.265963 8.778407<br>
O 9.655647 9.599469 9.660658<br>
O 10.309278 8.716008 8.623187<br>
H 12.602271 10.172732 14.171242<br>
O 12.548670 10.660947 13.362317<br>
O 13.376187 10.533582 0.248283<br>
H 2.382078 3.112711 2.361329<br>
O 2.319961 3.996877 2.712884<br>
O 3.309781 2.893447 2.471644<br>
H 0.187558 4.340477 8.250686<br>
O 0.976324 4.352700 7.700495<br>
O 0.325105 3.592681 8.832424<br>
H 11.659327 13.588808 0.140072<br>
O 10.701608 13.548170 0.199567<br>
O 11.868008 13.242048 13.640385<br>
H 8.818772 11.915113 8.170347<br>
O 9.160246 11.026199 8.156220<br>
O 7.876547 11.825312 7.972383<br>
H 6.953861 2.263551 5.723934<br>
O 7.336427 2.562735 4.895815<br>
O 6.885956 3.060728 6.255275<br>
H 11.442463 7.477512 8.438407<br>
O 12.075532 7.198556 9.069157<br>
O 11.189573 6.672282 7.958267<br>
H 5.984810 11.452681 7.625950<br>
O 5.728554 10.574700 7.945014<br>
O 5.752343 11.454954 6.692076<br>
H 8.931983 5.294554 4.433915<br>
O 9.734654 5.707683 4.109957<br>
O 9.238577 4.639954 5.081587<br>
H 11.828368 5.378873 6.956136<br>
O 12.465835 4.970816 7.538112<br>
O 12.336737 5.609106 6.175822<br>
H 7.301143 8.610338 7.491834<br>
O 8.019254 8.945782 8.007879<br>
O 7.554967 8.781518 6.582434<br>
H 2.741984 0.009479 4.583960<br>
O 2.325315 13.652372 5.050994<br>
O 1.999228 0.437728 4.150440<br>
H 4.078126 4.480106 9.256640<br>
O 3.532034 4.273291 8.466345<br>
O 3.819014 5.370796 9.487585<br>
H 4.777059 7.388148 14.094417<br>
O 4.798602 6.900684 13.257178<br>
O 5.480806 6.997436 0.231650<br>
H 1.009654 8.870862 3.650558<br>
O 0.610210 8.418493 2.883665<br>
O 1.631243 8.220421 4.008205</div>
<div><br>
</div>
<div><br>
</div>
<div>Thank you</div>
<div>Regards,</div>
<div><br>
</div>
<div>Vidushi Sharma</div>
<div>PhD student, Computational Condensed Matter Physics,</div>
<div>Stony Brook University,</div>
<div>NY-11780<br>
</div>
<div><br>
</div>
<div><br>
</div>
</div>
</div>
</blockquote></div>