<div dir="ltr">Dear quantum espresso user's<div>i have tried to run pw calculaion for a 44 atoms surface slab model of ZnO using the next input file;</div><div><br></div><div><div>&CONTROL</div><div> title = ZnO ,</div>
<div> calculation = 'relax' ,</div><div> max_seconds = 190000 ,</div><div> restart_mode = 'from_scratch' ,</div><div> outdir = 'C:/cygwin/home/pbe/' ,</div>
<div> wfcdir = 'C:/cygwin/home/pbe/' ,</div><div> pseudo_dir = 'C:/cygwin/home/pbe/' ,</div><div> prefix = 'ZnO' ,</div><div> lkpoint_dir = .false. ,</div>
<div> disk_io = 'high' ,</div><div> etot_conv_thr = 1.0D-6 ,</div><div> forc_conv_thr = 1.0D-4 ,</div><div> tstress = .true. ,</div><div> tprnfor = .true. ,</div>
<div> tefield = .true. ,</div><div> dipfield = .true. ,</div><div> lelfield = .false. ,</div><div> lberry = .false. ,</div><div> /</div><div> &SYSTEM</div>
<div> ibrav = 4,</div><div> celldm(1) = 12.358357076,</div><div> celldm(3) = 3.200,</div><div> nat = 44,</div><div> ntyp = 3,</div>
<div> ecutwfc = 50 ,</div><div> ecutrho = 200 ,</div><div> nosym = .false. ,</div><div> tot_charge = 0.000000,</div><div> occupations = 'smearing' ,</div>
<div> degauss = 0.001 ,</div><div> smearing = 'gaussian' ,</div><div> lda_plus_u = .false. ,</div><div> /</div><div> &ELECTRONS</div><div> electron_maxstep = 50,</div>
<div> conv_thr = 1.0D-5 ,</div><div> mixing_beta = 0.7 ,</div><div> /</div><div> &IONS</div><div> ion_dynamics = 'bfgs' ,</div><div> /</div><div>ATOMIC_SPECIES</div>
<div> Zn 65.39000 zn205.cpi.UPF </div><div> O 15.99900 onrr.cpi.UPF </div><div> H 1.00740 hh.cpi.UPF </div><div>ATOMIC_POSITIONS angstrom </div><div> H 0.000000000 0.000000000 0.242600000 0 0 0 </div>
<div> O 0.000000000 1.887819846 2.595050188 0 0 0 </div><div> Zn 0.000000000 0.000000000 1.972653799 0 0 0 </div><div> Zn 0.000000000 1.887819846 4.567759359 0 0 0 </div>
<div> H 3.269799948 0.000000000 0.242600000 0 0 0 </div><div> O 3.269799948 1.887819846 2.595050188 0 0 0 </div><div> Zn 3.269799948 0.000000000 1.972653799 0 0 0 </div>
<div> Zn 3.269799948 1.887819846 4.567759359 0 0 0 </div><div> H -1.634899974 2.831729820 0.242600000 0 0 0 </div><div> O -1.634899974 4.719549666 2.595050188 0 0 0 </div>
<div> Zn -1.634899974 2.831729820 1.972653799 0 0 0 </div><div> Zn -1.634899974 4.719549666 4.567759359 0 0 0 </div><div> H 1.634899974 2.831729820 0.242600000 0 0 0 </div>
<div> O 1.634899974 4.719549666 2.595050188 0 0 0 </div><div> Zn 1.634899974 2.831729820 1.972653799 0 0 0 </div><div> Zn 1.634899974 4.719549666 4.567759359 0 0 0 </div>
<div> O 0.000000000 0.000000000 5.189899921 </div><div> O 0.000000000 1.887819846 7.784950109 </div><div> Zn 0.000000000 0.000000000 7.162553721 </div><div> Zn 0.000000000 1.887819846 9.757659281 </div>
<div> O 3.269799948 0.000000000 5.189899921 </div><div> O 3.269799948 1.887819846 7.784950109 </div><div> Zn 3.269799948 0.000000000 7.162553721 </div><div> Zn 3.269799948 1.887819846 9.757659281 </div>
<div> O -1.634899974 2.831729820 5.189899921 </div><div> O -1.634899974 4.719549666 7.784950109 </div><div> Zn -1.634899974 2.831729820 7.162553721 </div><div> Zn -1.634899974 4.719549666 9.757659281 </div>
<div> O 1.634899974 2.831729820 5.189899921 </div><div> O 1.634899974 4.719549666 7.784950109 </div><div> Zn 1.634899974 2.831729820 7.162553721 </div><div> Zn 1.634899974 4.719549666 9.757659281 </div>
<div> O 0.000000000 0.000000000 10.379799843 </div><div> O 0.000000000 1.887819846 12.974850030 </div><div> Zn 0.000000000 0.000000000 12.352453642 </div><div> O 3.269799948 0.000000000 10.379799843 </div>
<div> O 3.269799948 1.887819846 12.974850030 </div><div> Zn 3.269799948 0.000000000 12.352453642 </div><div> O -1.634899974 2.831729820 10.379799843 </div><div> O -1.634899974 4.719549666 12.974850030 </div>
<div> Zn -1.634899974 2.831729820 12.352453642 </div><div> O 1.634899974 2.831729820 10.379799843 </div><div> O 1.634899974 4.719549666 12.974850030 </div><div> Zn 1.634899974 2.831729820 12.352453642 </div>
<div>K_POINTS automatic </div><div> 4 4 1 0 0 0 </div></div><div><br></div><div>however the convergence was failed</div><div>i have tried o use different K points mesh such as 3x3x1 or 5x5x1 but the problem is the same. i have changed the vacum region from 10 to 15 A, i have used the dipole correction also but the convergence problem was not resolved </div>
<div>so if any one have a solution le me know</div><div>best regards</div></div>