<div dir="ltr"><div><div>Hi,<br><br></div>I am running pw.x simulations with a slab of quartz (Si-O2) plus one molecule of water (H2O). I am varying the distance between the quartz and the water and minimizing the energy to obtain the electron density. For some simulations, this runs perfectly fine. But for a range of distances, the simulation is not converging.<br><br></div><div>I am running version 5.2.1.<br><br></div><div>Here is an example input for a simulation that did not converge:<br>&control<br> calculation='scf',<br> wf_collect = .true. ,<br> outdir = 'bulkQuartz' ,<br> restart_mode = 'restart' ,<br> pseudo_dir = 'pseudo' ,<br> disk_io = 'low' ,<br> verbosity = 'low' ,<br> max_seconds = 100000 ,<br> /<br> &system<br> ibrav = 4 ,<br> celldm(1)=19.174,<br> celldm(3)=11,<br> nat = 99 ,<br> ntyp = 3 ,<br> ecutwfc = 40.0,<br> ecutrho = 400.0,<br> smearing='mp',<br> occupations='smearing',<br> degauss=0.03,<br> /<br> &electrons<br> diagonalization='david',<br> conv_thr = 1.d-9,<br> mixing_mode = 'plain',<br> mixing_beta = 0.3,<br> /<br> &ions<br> /<br>ATOMIC_SPECIES<br>Si 28.086 Si.pbe-n-rrkjus_psl.0.1.UPF<br>O 15.9994 O.pbe-n-rrkjus_psl.0.1.UPF<br>H 1.0008 H.pbe-rrkjus_psl.0.1.UPF<br>ATOMIC_POSITIONS crystal<br>Si 0.258687845 0.020629154 0.102019210<br>Si -0.019888278 0.217277596 0.135661396<br>Si -0.255311356 -0.249612076 0.118530505<br>O 0.216500358 0.131658292 0.109534141<br>O 0.105223826 0.186083494 0.128659197<br>O 0.264534959 -0.168589142 0.143893618<br>O -0.226733650 -0.091440817 0.112415255<br>O -0.094524332 -0.210925541 0.123877363<br>O 0.093345754 -0.085570018 0.095442520<br>Si 0.757637856 0.017698785 0.102996627<br>Si 0.499261195 0.247760755 0.133810675<br>Si 0.260502898 -0.231081580 0.118523575<br>O 0.715128665 0.136375843 0.108242265<br>O 0.614018644 0.199922131 0.127663208<br>O 0.377640707 0.099030305 0.140774042<br>O 0.292700056 -0.078156587 0.111965605<br>O 0.414396516 -0.210945055 0.124328613<br>O 0.577963780 -0.097510873 0.096335619<br>Si 0.246470371 0.510075455 0.102784084<br>Si -0.008350761 0.743445657 0.133843274<br>Si -0.243372898 0.263323249 0.118704908<br>O 0.222512928 0.641672436 0.108318043<br>O 0.110306465 0.704860221 0.126807033<br>O -0.115606042 0.588684590 0.140894836<br>O -0.207914965 0.421714663 0.112788923<br>O -0.098241029 0.274413059 0.125535627<br>O 0.089954168 0.409350420 0.095091556<br>Si 0.228636707 -0.015515213 0.148652077<br>Si -0.000570920 0.240108188 0.180788870<br>Si -0.238830414 -0.233101222 0.164455135<br>O 0.188814156 0.105300171 0.155401485<br>O 0.129580597 0.211975161 0.174891343<br>O -0.103849604 0.085600484 0.188142180<br>O -0.197719806 -0.075671535 0.157544568<br>O -0.081306989 -0.212395019 0.169818898<br>O 0.059546539 -0.110377315 0.142459206<br>Si 0.740429584 0.504294772 0.102333982<br>Si 0.498815103 0.741901797 0.134296099<br>Si 0.248787099 0.256703622 0.119466045<br>O 0.690620417 0.619909718 0.108736776<br>O 0.615675562 0.693188124 0.128587271<br>O 0.372773731 0.591011105 0.141039660<br>O 0.272376153 0.410198382 0.112966911<br>O 0.413019149 0.304455349 0.124924356<br>O 0.584007175 0.392416303 0.095402910<br>Si 0.758429580 0.021916104 0.148368885<br>Si 0.497195902 0.241475081 0.180701057<br>Si 0.256420844 -0.246383404 0.165486299<br>O 0.696874500 0.124690779 0.154915749<br>O 0.627049328 0.207421194 0.175351188<br>O 0.389596957 0.095713470 0.188773822<br>O 0.286106670 -0.081604242 0.160344849<br>O 0.420928926 -0.211470046 0.169927370<br>O 0.605226550 -0.102009143 0.141361730<br>Si 0.230900257 0.494107246 0.150078925<br>Si -0.002502177 0.742290132 0.180741181<br>Si -0.245952687 0.256039707 0.165008027<br>O 0.185533611 0.602815647 0.157314135<br>O 0.131608578 0.714161757 0.175650111<br>O -0.109986238 0.584469784 0.187280614<br>O -0.213559651 0.414224396 0.159154408<br>O -0.089358513 0.275030823 0.170099821<br>O 0.075256561 0.370294522 0.143692679<br>Si 0.739384104 0.504889521 0.149819448<br>Si 0.501511397 0.743531243 0.180792889<br>Si 0.252716537 0.245693266 0.164465906<br>O 0.692669670 0.623114374 0.155320753<br>O 0.632713148 0.718738485 0.174634131<br>O 0.390256052 0.587279847 0.187506439<br>O 0.287331354 0.401942568 0.158203482<br>O 0.413978743 0.277476084 0.169723547<br>O 0.591741413 0.389802030 0.142457721<br>O 0.075025371 0.394019373 0.189188206<br>O 0.585313746 0.402337676 0.188308620<br>O 0.586281012 0.898771216 0.188916607<br>O 0.079369486 0.894756829 0.189163605<br>H 0.279938155 0.524595442 0.186664674<br>H 0.554383154 0.470114112 0.184420140<br>H 0.559654896 0.970318831 0.185076636<br>H 0.054346688 0.968508631 0.185624074<br>H 0.048603107 0.467541718 0.185794537<br>H -0.222446062 0.525660848 0.186700053<br>H 0.277389445 0.032971149 0.187895233<br>H -0.214394328 0.027904448 0.187751258<br>O 0.412416352 0.098886746 0.094609920<br>O 0.902446164 0.097353509 0.094335582<br>O 0.893185184 0.601781350 0.094504311<br>O 0.414681469 0.606997644 0.095511698<br>H 0.486522220 0.570599213 0.098078251<br>H 0.523150719 0.275802926 0.095532467<br>H 1.020421053 0.445893853 0.097845531<br>H 1.027748221 -0.046877912 0.098118747<br>H 0.513764581 -0.217924054 0.096610529<br>H 0.509415048 -0.057382202 0.098654295<br>H -0.039562544 -0.290584834 0.096265488<br>H -0.030986477 0.209885972 0.095356879<br>H 0.003452399 0.090676042 0.305 # Does not converge from 0.305 to 0.355. <br>H 0.090676042 0.003452399 0.305 #
Everything else I tried (0.205 to 0.280 and also 0.455) converged.
<br>O 0.105871559 0.105871559 0.305<br>K_POINTS automatic<br>1 1 1 1 1 1<br><br>- - - - - <br><br></div><div>And the output of the last few steps before max_cpu time is reached:<br></div><div> iteration #149 ecut= 40.00 Ry beta=0.30<br> Davidson diagonalization with overlap<br> ethr = 8.11E-07, avg # of iterations = 1.0<br><br> negative rho (up, down): 8.983E-03 0.000E+00<br><br> total cpu time spent up to now is 96700.7 secs<br><br> total energy = -2222.09469556 Ry<br> Harris-Foulkes estimate = -2222.09477676 Ry<br> estimated scf accuracy < 0.00452085 Ry<br><br> iteration #150 ecut= 40.00 Ry beta=0.30<br> Davidson diagonalization with overlap<br> ethr = 8.11E-07, avg # of iterations = 1.0<br><br> negative rho (up, down): 8.982E-03 0.000E+00<br><br> total cpu time spent up to now is 97153.1 secs<br><br> total energy = -2222.09453313 Ry<br> Harris-Foulkes estimate = -2222.09469588 Ry<br> estimated scf accuracy < 0.00440438 Ry<br><br> iteration #151 ecut= 40.00 Ry beta=0.30<br> Davidson diagonalization with overlap<br> ethr = 8.11E-07, avg # of iterations = 1.0<br><br> negative rho (up, down): 8.992E-03 0.000E+00<br><br> total cpu time spent up to now is 97606.0 secs<br><br> total energy = -2222.09363527 Ry<br> Harris-Foulkes estimate = -2222.09453414 Ry<br> estimated scf accuracy < 0.00423049 Ry<br><br> iteration #152 ecut= 40.00 Ry beta=0.30<br> Davidson diagonalization with overlap<br><br> Maximum CPU time exceeded<br><br> - - - - -<br><br></div><div>Best Regards,<br><br></div><div>Dan Gil<br></div><div>PhD Student <br></div><div>Department of Chemical and Biomolecular Engineering<br>Case Western Reserve University<br></div><div><br></div></div>