<div dir="ltr"><div dir="ltr">Dear Sir,<div>Thanks for your reply.</div><div>It is very useful for me.</div><div>Consider my apology for late reply as my computer was not free.</div><div><br></div><div>ecutrho 52 is by mistake. actually it is 520 (uspp).</div><div><br></div><div>I tried to run calculations for "V" but I could not finish pp.x.</div><div>I run pw.x followed by pp.x.</div><div><br></div><div>my <a href="http://pp.in" target="_blank">pp.in</a> is</div><div><br></div><div>&inputPP<br> prefix = 'pwscf'<br> outdir='/tmp-$i',<br> plot_num=11<br> filplot = 'pp-$i.pot'<br>/<br> <br>&plot<br> iflag=3,<br> output_format=5<br>/<br></div><div><br></div><div>where prefix and outdir is same as I used in in my scf file.</div><div><br></div><div>I am getting below xml error</div><div><br></div><div> Error in routine pw_readschemafile (1):<br> xml data file not found<br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br><br> stopping ...<br><br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br> Error in routine pw_readschemafile (1):<br> xml data file not found<br> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%<br><br> stopping ..<br></div><div><br></div><div>Please suggest me how to run pp.x.</div><div><br></div><div>My problem is related with <a href="https://lists.quantum-espresso.org/pipermail/users/2017-November/039771.html"> this issue</a> but I am not doing any restart_mode calculation.</div><div><br></div><div><br></div><div>Best Wishes,</div><div><br></div><div>Rekha</div><div><br></div><div><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Thu, Jan 2, 2020 at 6:50 PM Lucas Nicolás Lodeiro Moraga <<a href="mailto:lucas.lodeiro@ug.uchile.cl" target="_blank">lucas.lodeiro@ug.uchile.cl</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 dir="ltr"><div>Hello Rekha!</div><div>I am not an expert in monolayers, I work with slabs, but the problems should be similar. <br></div><div>First, the ecutrho value that you use (52) it is very low... I do not know wich type of pseudopotential do you use (NormConserving, UltraSoft, PAW), but the ecutrho must be 4 times the ecutwfc (For US and PAW form 6 to 12 times). Other thing, the convergence criteria of 1meV its good, but I prefer a criteria independent of number of atoms, as 1meV/atom... If you have the same system with more atoms, with your criteria you need a higher values to reach ir, but if use an independent atoms criteria, the values are the same for small and big systems.</div><div><br></div><div>MONOLAYER:</div><div>kpoints: I use 1 point in the vacuum direction, and I do not found any difference when I use 2 or more kpoints in this direction. The bands dispersion in this direction is negligible.</div><div>cell: The 2Dshape flag does not change your cell because it does not change the xy area, how you have an orthogonal a,b vectors and a=b. The broken of this symmetry is energetically not allowed. For this, 2Dxy flag works and minimize the cell in xy directions, and reduce the stress.</div><div>If is it okay the parameters deviates from the bulk? I do not know for the case of Monolayers... but for me makes sense, in your calculation the xy area reduces to maximize the interaction with the neighborhood. If you want do a vc-relax the 2Dxy is the correct flag. <br></div><div>Vacuum: 30 bohr should be enough... In my systems I do a similar vacuum test, and 30 bohr gives the same result as 200 bohr.</div><div>I guess your system have charged surfaces, dipoles or something like that. If is a bynary semiconductor AB... a monolayer gives you a "A type" and a "B Type" surfaces, how A and B have different electronegativities, exists a dipole between both surfaces, that could explain the energy behaviour with vacuum.</div><div>I recommend, do a post-processing calculation for the monolayer, calculate the electrostatic potential (V) along the vacuum direction... If V is not plane in the vaccum region, do you have a dipole on the monolayer. You can fix it using a dip-field on the vacuum... with it you add a "V step" on the vacuum, giving you two V planes on vaccum, "two types of vaccum".</div><div>Other way, is making a monolayer with equal surfaces, like A-A or B-B (adding a plane of atoms)... this fix the dipole in most cases... but I do not know if this is still a monolayer or what you want.</div><div><br></div><div>Regards</div><div><br></div><div>Lucas Lodeiro<br></div><div><br></div></div>
</blockquote></div><br clear="all"><div><br></div>-- <br><div dir="ltr"><div dir="ltr"><div><font face="georgia, serif" size="4"><br></font></div><div><font face="georgia, serif" size="4"><br></font></div><div><font face="georgia, serif" size="4"><br></font></div><div><font face="georgia, serif" size="4"><br></font></div><div><font face="georgia, serif" size="4">Best wishes</font></div><div><font face="georgia, serif" size="4"><br></font></div><div><font face="georgia, serif" size="4">Ms. Rekha</font></div><div><font face="georgia, serif" size="4">Ex-PG student,</font></div><div><font face="georgia, serif" size="4">LBS college, Jaipur</font></div><div><font face="georgia, serif" size="4">India<br></font></div><div><font face="georgia, serif" size="4">Mob.: +11 90-95 790 71 697</font></div><div><font face="georgia, serif" size="4">Email: <a href="mailto:rekha1997jpr@gmail.com" target="_blank">rekha1997jpr@gmail.com</a></font></div></div></div></div>