<div>Dear Guido, Paolo, Giuseppe</div>
<div>I just wanted to tell you guys (and put this in the forum) that gaussian smearing with low convergence (1e-5) worked for Ni layer relaxation on Al2O3 slab as first step (with K meshing of 4 4 1). Later, I increased the convergence to 1e-8 and the runs finished successfully as well. Thanks for all your help and guidance.</div>
<div> </div>
<div>Best Regards,</div>
<div>Vikas <br></div>
<div>Getting ready for next set of simulations. <br></div>
<div class="gmail_quote">On Tue, Jan 24, 2012 at 11:14 AM, Guido Fratesi <span dir="ltr"><<a href="mailto:fratesi@mater.unimib.it">fratesi@mater.unimib.it</a>></span> wrote:<br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">
<div class="im">
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">I have not tired gaussian smearing. I will try that as well. I will also<br>reduce the k-mesh style to get to final coordinates quicker.<br>
How do I specify larger broadening. Sorry but I am new to QE so please<br>help here.<br></blockquote><br></div>sorry, it's the parameter called "degauss"
<div class="im"><br><br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">Yes you are very true to say that Ni Atoms are a bit closer than their<br>respective positions in crystal. As I wanted to lay down a Ni layer of<br>
Al2O3, I started with 1 1 1 plane of Ni (hexagonal symmetry) with to put<br>on top of Al2O3 (hexagonal symmetry). However as you see below, the unit<br>cell of Al2O3 is a little smaller than that of Ni, so, I compressed the<br>
Ni atoms a little bit so as to fit them in Al2O3 geometry.<br>Al2O3 a cell dimension = 4.789471<br>Ni a cell dimension (along 1 1 1) plane = 4.951255<br></blockquote><br></div>well, not that much indeed. Still some buckling could be expected, as you say below.
<div class="im"><br><br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">I could now very well see that is this could be a source of the problem.<br>In that case, what do you suggest? What about moving 2 of the 4 atoms in<br>
z direction so that distance between the atoms becomes similar to ~ what<br>it is in bulk crystal. I had nspin=2 (default) in my calculations.<br></blockquote><br></div>in the input posted to the forum there was no spin polarization. The default is nspin=1.<br>
<br>Regards,<br>Guido<br><br>
<blockquote style="BORDER-LEFT:#ccc 1px solid;MARGIN:0px 0px 0px 0.8ex;PADDING-LEFT:1ex" class="gmail_quote">
<div class="im">Should I change it to nspin = 1?<br>Thank you very much for the insights.<br>Best Regards,<br>Vikas<br>On Tue, Jan 24, 2012 at 10:35 AM, Guido Fratesi <<a href="mailto:fratesi@mater.unimib.it" target="_blank">fratesi@mater.unimib.it</a><br>
</div>
<div>
<div class="h5"><mailto:<a href="mailto:fratesi@mater.unimib.it" target="_blank">fratesi@mater.unimib.<u></u>it</a>>> wrote:<br><br> Have you tried with gaussian smearing, by chance? In a test I was<br> making sometimes ago with TiO2 slabs, that was more easy to converge<br>
than the other choices. A larger broadening could also help,<br> especially to get an initial configuration/charge to be refined<br> later, and you might want to reduce the kpoint mesh to speed up your<br> tests. Ni atoms look a bit (not too much) close which could be also<br>
source of problems: is the Ni overlayer compressed with respect to a<br> free-standing Ni layer in 2D? Finally, I guess you will be<br> interested in spin-polarized calculations at the end.<br> I'd be curious about what solves the problem, eventually.<br>
Guido<br><br> Il 01/24/2012 03:48 PM, Vikas Varshney ha scritto:<br><br> Dear Guido,<br> Sorry for the confusion, actually when I was copy pasting the<br> data on<br> the email from my input file, 3 lines got deleted by error.<br>
Number of<br> atoms are actually 34. 30 Al203 atoms for a unit cell and 4 Ni<br> atoms.<br> THe full positions are below.The bold lines were missing before.<br> Thanks<br> for looking into this.<br>
ATOMIC_POSITIONS angstrom<br> O 1.473346033 0.017326072 3.218609176<br></div></div>
<div class="im"> O <a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a> <tel:<a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a>> 1.378379317 <a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a><br>
<tel:<a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a>><br> O 1.513480866 2.829876285 11.933514340<br> O -0.751677351 1.267293591 3.218609163<br> O 1.663968734 2.656771683 7.574956486<br>
O -0.812749430 4.043578468 11.933514157<br> O 1.673065193 2.863185205 3.218609361<br> O 1.656654190 0.112656124 7.574956554<br> O -0.700731568 1.422153909 11.933514350<br>
O 3.298048338 0.005706615 9.773211485<br> O 0.927961928 1.382600916 1.089494747 0 0 0<br> O -1.464820834 2.766734881 5.396064047<br> O -1.653964847 2.853342545 9.773211296<br>
O <a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a> <tel:<a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a>> 0.112338146 1.089494747 0<br> 0 0<br>
O 0.731082457 1.495864856 5.396064158<br></div> *O 0.750650394 1.288758309 9.773211044<br><br> O <a href="tel:3.128121627" target="_blank" value="+13128121627">3.128121627</a> <tel:<a href="tel:3.128121627" target="_blank" value="+13128121627">3.128121627</a>> 2.652863759 1.089494747 0
<div class="im"><br> 0 0<br> O 0.733736896 4.033006936 5.396064408<br> *Al -0.000000812 0.000001493 4.556157709<br><br></div>
<div class="im"> Al <a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a> <tel:<a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a>> 1.382602298 8.876166342<br>
Al 0.000000000 2.765201880 0.243870515 0 0 0<br> Al 0.000000000 0.000000000 1.935118618 0 0 0<br></div> Al <a href="tel:2.394734540" target="_blank" value="+12394734540">2.394734540</a> <tel:<a href="tel:2.394734540" target="_blank" value="+12394734540">2.394734540</a>> 1.382602230 6.225550857
<div class="im"><br> Al -0.000000007 2.765202952 10.790402310<br> Al -0.000000362 0.000002278 8.430662634<br></div> Al <a href="tel:2.394735475" target="_blank" value="+12394735475">2.394735475</a> <tel:<a href="tel:2.394735475" target="_blank" value="+12394735475">2.394735475</a>> 1.382602563 12.021576409
<div class="im"><br> Al -0.000000581 2.765202130 4.047340256<br> Al 0.000000075 0.000002190 11.054412333<br></div> Al <a href="tel:2.394734840" target="_blank" value="+12394734840">2.394734840</a> <tel:<a href="tel:2.394734840" target="_blank" value="+12394734840">2.394734840</a>> 1.382601177 <a href="tel:2.258435418" target="_blank" value="+12258435418">2.258435418</a><br>
<tel:<a href="tel:2.258435418" target="_blank" value="+12258435418">2.258435418</a>>
<div class="im"><br> Al -0.000000323 2.765202460 6.730673987<br> Ni -0.016734 -0.025515 15.297379<br> Ni 1.180634 -2.099417 15.297379<br> Ni -1.214101 -2.099417 15.297379<br>
Ni -2.411469 -0.025515 15.297379<br> Best Regards,<br> Vikas<br><br> On Tue, Jan 24, 2012 at 3:46 AM, Guido Fratesi<br> <<a href="mailto:fratesi@mater.unimib.it" target="_blank">fratesi@mater.unimib.it</a> <mailto:<a href="mailto:fratesi@mater.unimib.it" target="_blank">fratesi@mater.unimib.<u></u>it</a>><br>
</div> <mailto:<a href="mailto:fratesi@mater.unimib." target="_blank">fratesi@mater.unimib.</a>_<u></u>_it
<div class="im"><br> <mailto:<a href="mailto:fratesi@mater.unimib.it" target="_blank">fratesi@mater.unimib.<u></u>it</a>>>> wrote:<br><br> Have you checked the input is read correctly? Apparently,<br>
the number of<br> atoms listed (31) does not correspond to "nat" (ii)<br> Guido<br><br> Il 01/23/2012 06:51 PM, Vikas Varshney ha scritto:<br> > &CONTROL<br> > calculation = 'relax' ,<br>
> restart_mode = 'from_scratch' ,<br> > wf_collect = .true. ,<br> > outdir = './' ,<br> > pseudo_dir =<br>
</div> '/lustre/app2/espresso/pseudo/<u></u>__' ,
<div>
<div class="h5"><br> > disk_io = 'default' ,<br> > verbosity = 'high' ,<br> > /<br> > &SYSTEM<br> > ibrav = 0,<br>
> celldm(1)= 9.050787,<br> > nat = 34,<br> > ntyp = 3,<br> > ecutwfc = 55 ,<br> > ecutrho = 550 ,<br>
> occupations = 'smearing' ,<br> > degauss = 0.01 ,<br> > smearing = 'methfessel-paxton' ,<br> > nosym = .true. ,<br>
> nosym_evc = .true. ,<br> > /<br> > &ELECTRONS<br> > conv_thr = 1.0D-4 ,<br> > diagonalization = 'david' ,<br>
> mixing_mode = 'local-TF' ,<br> > mixing_beta = 0.1 ,<br> > electron_maxstep = 500 ,<br> > /<br> > &IONS<br> > ion_dynamics = 'bfgs' ,<br>
> ion_positions = 'from_input' ,<br> > /<br> > CELL_PARAMETERS hexagonal<br> > 1.000000000 0.000000000 0.000000000<br> > 0.500000000 0.866025000 0.000000000<br>
> 0.000000000 0.000000000 10.824313000<br> > ATOMIC_SPECIES<br> > O 15.99940 O.pbe-van_ak.UPF<br> > Al 26.98154 Al.pbe-n-van.UPF<br> > Ni 58.69340 Ni.pbe-nd-rrkjus.UPF<br>
> ATOMIC_POSITIONS angstrom<br> > O 1.473346033 0.017326072 3.218609176<br></div></div> > O <a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a> <tel:<a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a>> <tel:<a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a>
<div class="im"><br> <tel:<a href="tel:3.863581042" target="_blank" value="+13863581042">3.863581042</a>>> 1.378379317 <a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a> <tel:<a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a>><br>
</div> <tel:<a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a> <tel:<a href="tel:7.574956508" target="_blank" value="+17574956508">7.574956508</a>>>
<div class="im"><br><br> > O 1.513480866 2.829876285 11.933514340<br> > O -0.751677351 1.267293591 3.218609163<br> > O 1.663968734 2.656771683 7.574956486<br> > O -0.812749430 4.043578468 11.933514157<br>
> O 1.673065193 2.863185205 3.218609361<br> > O 1.656654190 0.112656124 7.574956554<br> > O -0.700731568 1.422153909 11.933514350<br> > O 3.298048338 0.005706615 9.773211485<br>
> O 0.927961928 1.382600916 1.089494747 0 0 0<br> > O -1.464820834 2.766734881 5.396064047<br> > O -1.653964847 2.853342545 9.773211296<br></div> > O <a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a> <tel:<a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a>> <tel:<a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a>
<div class="im"><br> <tel:<a href="tel:3.128121670" target="_blank" value="+13128121670">3.128121670</a>>> 0.112338146 1.089494747 0<br><br> 0 0<br> > O 0.731082457 1.495864856 5.396064158<br>
> Al -0.000000812 0.000001493 4.556157709<br></div> > Al <a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a> <tel:<a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a>> <tel:<a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a>
<div class="im"><br> <tel:<a href="tel:2.394734647" target="_blank" value="+12394734647">2.394734647</a>>> 1.382602298 8.876166342<br><br> > Al 0.000000000 2.765201880 0.243870515 0 0 0<br>
> Al 0.000000000 0.000000000 1.935118618 0 0 0<br></div> > Al <a href="tel:2.394734540" target="_blank" value="+12394734540">2.394734540</a> <tel:<a href="tel:2.394734540" target="_blank" value="+12394734540">2.394734540</a>> 1.382602230 6.225550857
<div class="im"><br> > Al -0.000000007 2.765202952 10.790402310<br> > Al -0.000000362 0.000002278 8.430662634<br></div> > Al <a href="tel:2.394735475" target="_blank" value="+12394735475">2.394735475</a> <tel:<a href="tel:2.394735475" target="_blank" value="+12394735475">2.394735475</a>> 1.382602563 12.021576409
<div class="im"><br> > Al -0.000000581 2.765202130 4.047340256<br> > Al 0.000000075 0.000002190 11.054412333<br></div> > Al <a href="tel:2.394734840" target="_blank" value="+12394734840">2.394734840</a> <tel:<a href="tel:2.394734840" target="_blank" value="+12394734840">2.394734840</a>> 1.382601177 <a href="tel:2.258435418" target="_blank" value="+12258435418">2.258435418</a><br>
<tel:<a href="tel:2.258435418" target="_blank" value="+12258435418">2.258435418</a>>
<div class="im"><br> > Al -0.000000323 2.765202460 6.730673987<br> > Ni -0.016734 -0.025515 15.297379<br> > Ni 1.180634 -2.099417 15.297379<br>
> Ni -1.214101 -2.099417 15.297379<br> > Ni -2.411469 -0.025515 15.297379<br> > K_POINTS automatic<br> > 4 4 1 0 0 0<br><br> --<br>
Guido Fratesi<br><br> Dipartimento di Scienza dei Materiali<br> Universita` degli Studi di Milano-Bicocca<br> via Cozzi 53, 20125 Milano, Italy<br></div> ______________________________<u></u>___________________
<div class="im"><br> Pw_forum mailing list<br> <a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a> <mailto:<a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a>><br>
</div> <mailto:<a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a> <mailto:<a href="mailto:Pw_forum@pwscf.org" target="_blank">Pw_forum@pwscf.org</a>>><br> <a href="http://www.democritos.it/__mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/__<u></u>mailman/listinfo/pw_forum</a>
<div class="im"><br> <<a href="http://www.democritos.it/mailman/listinfo/pw_forum" target="_blank">http://www.democritos.it/<u></u>mailman/listinfo/pw_forum</a>><br><br><br><br> --<br> Guido Fratesi<br><br>
Dipartimento di Scienza dei Materiali<br> Universita` degli Studi di Milano-Bicocca<br> via Cozzi 53, 20125 Milano, Italy<br><br><br></div></blockquote>
<div class="HOEnZb">
<div class="h5"><br>-- <br>Guido Fratesi<br><br>Dipartimento di Scienza dei Materiali<br>Universita` degli Studi di Milano-Bicocca<br>via Cozzi 53, 20125 Milano, Italy<br></div></div></blockquote></div><br>